Back contact battery and photovoltaic module

Abstract

The invention discloses a back contact cell and a photovoltaic module, relates to the technical field of photovoltaic, and aims to change the transmission path of light on the surface of a first area and / or a second area corresponding to the back contact cell through an island-shaped passivation structure and increase the double-sided rate of the back contact cell. The back contact battery comprises a semiconductor substrate, a first doped semiconductor layer, a second doped semiconductor layer and an island-shaped passivation structure. The semiconductor substrate has a first surface and a second surface opposite to each other. The first face comprises first areas and second areas which are alternately distributed. The first doped semiconductor layer is disposed on the first region. The second doped semiconductor layer is disposed on the second region. The conductive types of the second doped semiconductor layer and the first doped semiconductor layer are opposite. The island-shaped passivation structure is arranged on the side, away from the semiconductor substrate, of the first doped semiconductor layer and / or the second doped semiconductor layer, and / or the island-shaped passivation structure is arranged between the first doped semiconductor layer and / or the second doped semiconductor layer and the semiconductor substrate.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and particularly to a back-contact battery 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 light utilization rate on the back side of the existing back-contact battery is relatively low, which is not conducive to improving the bifaciality of the back-contact battery. Summary of the Invention

[0004] The purpose of this application is to provide a back-contact battery and a photovoltaic module, which are used to change the transmission path of light at the surface of the corresponding first region and / or second region of the back-contact battery through an island-shaped passivation structure, which is beneficial to refract more light from the first doped semiconductor layer / or the second doped semiconductor layer into the battery, improve the light utilization rate on the back side of the back-contact battery, and increase the bifaciality of the back-contact battery.

[0005] To achieve the above object, in a first aspect, this application provides a back-contact battery. The back-contact battery includes: a semiconductor substrate, a first doped semiconductor layer, a second doped semiconductor layer, and an island-shaped passivation structure. The semiconductor substrate has opposite first and second surfaces. The first surface includes alternately distributed first and second regions. The first doped semiconductor layer is disposed on the first region. The second doped semiconductor layer is disposed on the second region. The conductivity types of the second doped semiconductor layer and the first doped semiconductor layer are opposite. The island-shaped passivation structure is disposed on the side of the first doped semiconductor layer and / or the second doped semiconductor layer facing away from the semiconductor substrate, and / or, the island-shaped passivation structure is disposed between the first doped semiconductor layer and / or the second doped semiconductor layer and the semiconductor substrate.

[0006] When the back-contact battery is in the working state, the first doped semiconductor layer and the second doped semiconductor layer can effectively shunt and collect carriers, which is beneficial to the formation of photocurrent. The island-shaped passivation structure provided in the back-contact battery has a passivation function on the one hand. It can passivate the surface of the region where the island-shaped passivation structure is formed, reduce the number of defects on the region surface, and reduce the carrier recombination rate. On the other hand, it can change the transmission path of the incident light (such as increasing the reflection path of the incident light), which is beneficial to more incident light refracting into the battery, improving the absorption ratio of the incident light, and improving the bifaciality of the back-contact battery. Taking the example that the island-shaped passivation structure is arranged on the side of the first doped semiconductor layer facing away from the semiconductor substrate: The island-shaped passivation structure has a passivation function and can strengthen the passivation of the surface of the region where the island-shaped passivation structure is formed. In addition, the island-shaped passivation structure does not belong to a part of the first doped semiconductor layer. It is an additional passivation structure arranged on the side of the first doped semiconductor layer facing away from the semiconductor substrate and having an island shape. There may be a certain height difference between the island-shaped passivation structure and the side of the first doped semiconductor layer facing away from the semiconductor substrate, or there are differences in the materials between the island-shaped passivation structure and the first doped semiconductor layer, so that the island-shaped passivation structure can reflect or refract the incident light on the first side of the back-contact battery, change the transmission path of the incident light (such as increasing the reflection path of the incident light), which is beneficial to more incident light refracting into the battery, improving the absorption ratio of the incident light, and improving the bifaciality of the back-contact battery.

[0007] In addition, the application principle of the beneficial effects when the island-shaped passivation structure is arranged on the side of the second doped semiconductor layer facing away from the semiconductor substrate, and when the island-shaped passivation structure is arranged between the first doped semiconductor layer and / or the second doped semiconductor layer and the semiconductor substrate is the same as that when the island-shaped passivation structure is arranged on the side of the first doped semiconductor layer facing away from the semiconductor substrate, and will not be elaborated here. It should be noted that when the island-shaped passivation structure is arranged on the side of the second doped semiconductor layer facing away from the semiconductor substrate, the island-shaped passivation structure does not belong to a part of the second doped semiconductor layer and is a passivation structure additionally arranged outside the second doped semiconductor layer. When the island-shaped passivation structure is arranged between the first doped semiconductor layer and the semiconductor substrate, the island-shaped passivation structure belongs to neither the first doped semiconductor layer nor the semiconductor substrate and is a passivation structure additionally arranged outside the first doped semiconductor layer and the semiconductor substrate. When the island-shaped passivation structure is arranged between the second doped semiconductor layer and the semiconductor substrate, the island-shaped passivation structure belongs to neither the second doped semiconductor layer nor the semiconductor substrate and is a passivation structure additionally arranged outside the second doped semiconductor layer and the semiconductor substrate.

[0008] As a possible implementation scheme, at least one island-shaped passivation structure includes a plurality of dot-shaped passivation parts that are not adjacent to each other and are distributed in an aggregated manner; and / or, different regions of at least one island-shaped passivation structure are continuously distributed, and the surface of the island-shaped passivation structure has a fluctuating topography.

[0009] When the island-shaped passivation structure includes a plurality of dot-shaped passivation parts that are not adjacent to each other and are distributed in an aggregated manner, it is beneficial to increase the specific surface area of a single island-shaped passivation structure, increase the light absorption area of a single island-shaped passivation structure, enhance the light trapping effect of the island-shaped passivation structure, and further improve the incident light absorption ratio and the bifaciality of the back-contact battery. The application principle of the beneficial effect when different regions of at least one island-shaped passivation structure are continuously distributed and the surface of the island-shaped passivation structure has a undulating topography can refer to the application principle of the beneficial effect of the island-shaped passivation structure including a plurality of dot-shaped passivation parts that are not adjacent to each other and are distributed in an aggregated manner as described above. Secondly, another example can also be provided for the topography of the island-shaped passivation structure, which improves the applicability of the back-contact battery provided in this application in different application scenarios and reduces the process difficulty of manufacturing the back-contact battery. It should be noted that in the back-contact battery provided in this application, there can be simultaneously an island-shaped passivation structure including a plurality of dot-shaped passivation parts that are not adjacent to each other and are distributed in an aggregated manner, and an island-shaped passivation structure with continuously distributed different regions and a undulating surface topography.

[0010] As a possible implementation solution, the edge of the island-shaped passivation structure is in an irregular shape. This is beneficial for the island-shaped passivation structure to have side surfaces arranged in different directions, so that light incident from different directions can be reflected or refracted, which is beneficial for more incident light to be refracted into the battery, and further improves the incident light absorption ratio and the bifaciality of the back-contact battery. It should be noted that when the island-shaped passivation structure includes a plurality of dot-shaped passivation parts that are not adjacent to each other and are distributed in an aggregated manner, the edge of the island-shaped passivation structure refers to the edge of the region occupied by the plurality of dot-shaped passivation parts that are not adjacent to each other and are distributed in an aggregated manner as a whole. When different regions of the island-shaped passivation structure are continuously distributed, the edge of the island-shaped passivation structure refers to the edge surrounded by the continuously distributed different regions.

[0011] As a possible implementation solution, at least part of the island-shaped passivation structures are regularly distributed. The distribution pattern can be set according to the interaction characteristics between the incident light and the island-shaped passivation structures, so as to regularly reflect or refract the incident light on one side of the first surface of the back-contact battery, and be used in combination with the self-irregular light trapping of the island-shaped passivation structures to maximize the utilization of the incident light, and is also conducive to further improving the self-light trapping effect of the island-shaped passivation structures. Or, due to the island-shaped passivation structures being provided between the first doped semiconductor layer and / or the second doped semiconductor layer and the semiconductor substrate, the side of the first doped semiconductor layer and / or the second doped semiconductor layer facing away from the semiconductor substrate has a high light trapping effect, reducing the light shielding effect, and further increasing the incident light absorption ratio and the bifaciality of the back-contact battery. In the actual application process, in the back-contact battery, which island-shaped passivation structures are regularly distributed can be determined according to the light trapping requirements of different regions on the back side of the battery, and no specific limitation is made here. It can be that only the different island-shaped passivation structures provided on the side of the first doped semiconductor layer and / or the second doped semiconductor layer facing away from the semiconductor substrate are regularly distributed, or only the different island-shaped passivation structures provided between the first doped semiconductor layer and / or the second doped semiconductor layer and the semiconductor substrate are regularly distributed, or all the island-shaped passivation structures included in the back-contact battery are regularly distributed.

[0012] As a possible implementation solution, the distance between two adjacent island-shaped passivation structures is greater than or equal to 40 μm and less than or equal to 300 μm.

[0013] Setting the distance between two adjacent island-shaped passivation structures within the above range can prevent the distribution density of the island-shaped passivation structures provided on the semiconductor substrate from being too high due to the small distance between two adjacent island-shaped passivation structures, which affects the formation quality of the first doped semiconductor layer and / or the second doped semiconductor layer on the island-shaped passivation structures. Or, when the island-shaped passivation structure includes a doped semiconductor passivation part and the doped semiconductor passivation part has a conductivity type opposite to that of the adjacent first doped semiconductor layer or second doped semiconductor layer, it can prevent the leakage risk between the island-shaped passivation structure and the first doped semiconductor layer or the second doped semiconductor layer from being relatively high due to the small distance between two adjacent island-shaped passivation structures. By controlling the distance between two adjacent island-shaped passivation structures, the distribution density of the island-shaped passivation structures is controlled to ensure that the carrier recombination rate is within a controllable range. In addition, it can also prevent the light trapping effect on the side of the first surface of the back-contact battery from being poor due to the large distance between two adjacent island-shaped passivation structures, which is beneficial to having a high incident light absorption ratio on the side of the first surface and further increasing the bifaciality of the back-contact battery. It should be noted that the distance between two adjacent island-shaped passivation structures refers to the minimum distance between the edges of two adjacent island-shaped passivation structures.

[0014] As a possible implementation, both the first doped semiconductor layer and the second doped semiconductor layer include strip-shaped doped regions; the strip-shaped doped regions included in the first doped semiconductor layer and the strip-shaped doped regions included in the second doped semiconductor layer both extend along a first direction and are alternately spaced along a second direction; the first direction is different from the second direction; the distance between two adjacent island-shaped passivation structures along the first direction is less than the distance between two adjacent island-shaped passivation structures along the second direction.

[0015] It can be understood that the length of the strip-shaped doped region is greater than the width of the strip-shaped doped region, and the light trapping requirement along the length direction (i.e., the first direction) of the strip-shaped doped region is greater than the light trapping requirement along the width direction (i.e., the second direction) of the strip-shaped doped region. Therefore, the different distances between the island-shaped passivation structures along the first direction and the second direction can respectively meet the different light trapping requirements along the first direction and the second direction, so that the adjacent island-shaped passivation structures along the first direction have a higher light trapping effect, further improving the bifaciality of the back contact battery.

[0016] As a possible implementation, at least one island-shaped passivation structure includes a doped semiconductor passivation portion; and / or, at least one island-shaped passivation structure includes an interface passivation portion; and / or, at least one island-shaped passivation structure includes a doped semiconductor passivation portion and a doped silicon glass portion provided on the side of the doped semiconductor passivation portion facing away from the semiconductor substrate.

[0017] The island-shaped passivation structure can be formed by manufacturing at least the doped semiconductor passivation portion, the interface passivation portion, and the doped silicon glass portion, which have good effects and are compatible with the battery manufacturing process. While making the island-shaped passivation structure have a good passivation effect, it can also improve the yield of the back contact battery. Different materials have different characteristics in terms of light absorption, light reflection, light refraction, etc. By combining different materials, the optical path can be changed to improve the light utilization rate. In addition, the doped semiconductor passivation portion, the interface passivation portion, and the doped silicon glass portion are also materials for manufacturing the back contact battery. At this time, the manufacturing of the island-shaped passivation structure can also be realized while manufacturing the corresponding structures in the back contact battery, improving the manufacturing efficiency of the back contact battery and simplifying the manufacturing process of the back contact battery.

[0018] As a possible implementation, in at least one island-shaped passivation structure provided on the side of the first doped semiconductor layer facing away from the semiconductor substrate, or, in at least one island-shaped passivation structure provided between the first doped semiconductor layer and the semiconductor substrate, the material and conduction type of the doped semiconductor passivation portion are the same as the material and conduction type of the second doped semiconductor layer, respectively. And / or, in at least one island-shaped passivation structure provided on the side of the second doped semiconductor layer facing away from the semiconductor substrate, or, in at least one island-shaped passivation structure provided between the second doped semiconductor layer and the semiconductor substrate, the material and conduction type of the doped semiconductor passivation portion are the same as the material and conduction type of the first doped semiconductor layer, respectively.

[0019] Taking the example that the material and conductivity type of the doped semiconductor passivation part included in the island-shaped passivation structure adjacent to the first doped semiconductor layer are respectively the same as the material and conductivity type of the second doped semiconductor layer, the island-shaped passivation structure adjacent to the first doped semiconductor layer can be manufactured while the second doped semiconductor layer is manufactured, thereby improving the manufacturing efficiency of the back contact battery and simplifying the manufacturing process of the back contact battery. The application principle of the beneficial effect that the material and conductivity type of the doped semiconductor passivation part included in the island-shaped passivation structure adjacent to the second doped semiconductor layer are respectively the same as the material and conductivity type of the first doped semiconductor layer can be referred to in the previous text and will not be repeated here.

[0020] As a possible implementation scheme, the back contact cell further includes a first interface passivation layer disposed between the semiconductor substrate and the first doped semiconductor layer, and a second interface passivation layer disposed between the semiconductor substrate and the second doped semiconductor layer. Among them, in at least one island-shaped passivation structure disposed on the side of the first doped semiconductor layer away from the semiconductor substrate, or in at least one island-shaped passivation structure disposed between the first doped semiconductor layer and the semiconductor substrate, the material of the interface passivation portion is the same as the material of the second interface passivation layer; and / or, in at least one island-shaped passivation structure disposed on the side of the second doped semiconductor layer away from the semiconductor substrate, or in at least one island-shaped passivation structure disposed between the second doped semiconductor layer and the semiconductor substrate, the material of the interface passivation portion is the same as the material of the first interface passivation layer. The application principle of the beneficial effect in this case can refer to the application principle of the beneficial effect of at least one island-shaped passivation structure disposed on the side of the first doped semiconductor layer away from the semiconductor substrate, or in at least one island-shaped passivation structure disposed between the first doped semiconductor layer and the semiconductor substrate, the material and conductivity type of the doped semiconductor passivation portion are respectively the same as the material and conductivity type of the second doped semiconductor layer, which will not be repeated here.

[0021] As a possible implementation, the back contact battery further includes a first doped silicon glass layer disposed on the side of the first doped semiconductor layer away from the semiconductor substrate, and a second doped silicon glass layer disposed on the side of the second doped semiconductor layer away from the semiconductor substrate. The first doped silicon glass layer has the same conductivity type as the first doped semiconductor layer. The second doped silicon glass layer has the same conductivity type as the second doped semiconductor layer. Among them, in at least one island-shaped passivation structure disposed on the side of the first doped semiconductor layer away from the semiconductor substrate, or in at least one island-shaped passivation structure disposed between the first doped semiconductor layer and the semiconductor substrate, the material and conductivity type of the doped silicon glass part are the same as those of the second doped silicon glass layer respectively; and / or, in at least one island-shaped passivation structure disposed on the side of the second doped semiconductor layer away from the semiconductor substrate, or in at least one island-shaped passivation structure disposed between the second doped semiconductor layer and the semiconductor substrate, the material and conductivity type of the doped silicon glass part are the same as those of the first doped silicon glass layer respectively. The application principle of the beneficial effects in this case can refer to the application principle of the beneficial effects that in at least one island-shaped passivation structure disposed on the side of the first doped semiconductor layer away from the semiconductor substrate, or in at least one island-shaped passivation structure disposed between the first doped semiconductor layer and the semiconductor substrate, the material and conductivity type of the doped semiconductor passivation part are the same as those of the second doped semiconductor layer respectively, which will not be elaborated here.

[0022] As a possible implementation, the island-shaped passivation structure disposed on the first region is located on the side of the first doped semiconductor layer away from the semiconductor substrate, and the island-shaped passivation structure disposed on the second region is disposed between the second doped semiconductor layer and the semiconductor substrate. Alternatively, the island-shaped passivation structure disposed on the first region is located between the first doped semiconductor layer and the semiconductor substrate, and the island-shaped passivation structure disposed on the second region is disposed on the side of the second doped semiconductor layer away from the semiconductor substrate.

[0023] The first doped semiconductor layer and the second doped semiconductor layer included in the back contact battery are respectively formed on the local area of ​​the first surface in different operation steps. In addition, in the process of manufacturing the first doped semiconductor layer and the second doped semiconductor layer, the patterned first doped semiconductor layer and the second doped semiconductor layer are obtained by selectively etching the doped semiconductor layer set in the whole layer. Therefore, the island-shaped passivation structure set on the first area is located on the side of the first doped semiconductor layer away from the semiconductor substrate, and the island-shaped passivation structure set on the second area is set between the second doped semiconductor layer and the semiconductor substrate. At this time, the first doped semiconductor layer can be manufactured first, and the island-shaped passivation structure set between the second doped semiconductor layer and the semiconductor substrate can be manufactured based on the part of the doped semiconductor material of the first doped semiconductor layer located in the second area. At the same time, after forming the first doped semiconductor layer and the island-shaped passivation structure set on the second area, the second doped semiconductor layer is manufactured, and the island-shaped passivation structure set on the side of the first doped semiconductor layer away from the semiconductor substrate can be manufactured based on the part of the doped semiconductor material of the second doped semiconductor layer located in the first area, which is conducive to improving the manufacturing efficiency of the back contact battery and simplifying the manufacturing process of the back contact battery.

[0024] As a possible implementation scheme, the area occupied by at least one island passivation structure is greater than or equal to 1 μm 2 , and less than or equal to 100μm 2 .

[0025] The area occupied by at least one island-shaped passivation structure is within the above range, which is conducive to preventing the passivation effect of the island-shaped passivation structure due to the small area occupied by the island-shaped passivation structure, and the island-shaped passivation structure itself or the island-shaped passivation structure. The light trapping effect is low, which is conducive to making the back contact battery have a higher double-sided rate. In addition, it can also prevent the formation quality of the first doped semiconductor layer and / or the second doped semiconductor layer formed on the island-shaped passivation structure from being affected due to the large area occupied by the island-shaped passivation structure, or when the island-shaped passivation structure includes a doped semiconductor passivation part, and the conductivity type of the doped semiconductor passivation part is opposite to that of the first doped semiconductor layer or the second doped semiconductor layer adjacent to itself, it can prevent the leakage risk of the battery from increasing due to the large area occupied by the island-shaped passivation structure, reduce the carrier recombination rate, and improve the working performance of the back contact battery.

[0026] As a possible implementation, the first surface further includes a spacer region located between the first region and the second region. Along the direction from the first surface to the second surface, the surface of the spacer region is recessed into the semiconductor substrate relative to the surface of the first region to form a groove structure. The groove structure has a first sidewall close to the first region and a second sidewall close to the second region. The first doped semiconductor layer has a first boundary close to the spacer region. The second doped semiconductor layer has a second boundary close to the spacer region. At least one island-shaped passivation structure is at least partially located between the first boundary and the first sidewall; and / or, at least one island-shaped passivation structure is at least partially located between the second boundary and the second sidewall.

[0027] To passivate the surface of the region of the semiconductor substrate where the island-shaped passivation structure is formed, reduce the number of defects on the region surface, and reduce the carrier recombination rate. In addition, the island-shaped passivation structure can change the transmission path of the incident light (such as increasing the reflection path of the incident light), which is beneficial for more incident light to be refracted into the battery, improve the absorption ratio of the incident light, and improve the bifaciality of the back contact battery. The island-shaped passivation structure does not belong to a part of the semiconductor substrate, and it is an additional passivation structure provided on the semiconductor substrate and having an island shape.

[0028] In a second aspect, 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 by the first aspect and its various implementation manners. The packaging layer covers the surface of the battery string.

[0029] For the beneficial effects of the second aspect and its various implementation manners in the present 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. Description of the Drawings

[0030] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0031] Figure 1 It is a longitudinal sectional schematic view of the first structure of the back contact battery provided by the embodiment of the present application;

[0032] Figure 2 It is a longitudinal sectional schematic view of the second structure of the back contact battery provided by the embodiment of the present application;

[0033] Figure 3 It is a partial structure OM on one side of the first surface of the back contact battery provided by the embodiment of the present application Figure 1 ;

[0034] Figure 4 It is a longitudinal sectional schematic view of the third structure of the back contact battery provided by the embodiment of the present application;

[0035] Figure 5 It is a longitudinal sectional view of the fourth structure of the back contact battery provided by the embodiment of the present application;

[0036] Figure 6 It is a longitudinal sectional view of the fifth structure of the back contact battery provided by the embodiment of the present application;

[0037] Figure 7 It is a longitudinal sectional view of the sixth structure of the back contact battery provided by the embodiment of the present application;

[0038] Figure 8 It is a longitudinal sectional view of the seventh structure of the back contact battery provided by the embodiment of the present application;

[0039] Figure 9 It is a longitudinal sectional view of the eighth structure of the back contact battery provided by the embodiment of the present application;

[0040] Figure 10 It is a partial structure OM on one side of the first surface of the back contact battery provided by the embodiment of the present application Figure 2 ;

[0041] Figure 11 It is a schematic diagram of the distribution relationship between the first doped semiconductor layer and the second doped semiconductor layer in the back contact battery provided by the embodiment of the present application Figure 1 ;

[0042] Figure 12 It is a schematic diagram of the distribution relationship between the first doped semiconductor layer and the second doped semiconductor layer in the back contact battery provided by the embodiment of the present application Figure 2 ;

[0043] Figure 13 It is a schematic diagram of the distribution relationship between the first doped semiconductor layer and the second doped semiconductor layer in the back contact battery provided by the embodiment of the present application Figure 3 ;

[0044] Figure 14 It is a longitudinal sectional view of the ninth structure of the back contact battery provided by the embodiment of the present application;

[0045] Figure 15 It is a longitudinal sectional view of the tenth structure of the back contact battery provided by the embodiment of the present application;

[0046] Figure 16 It is a longitudinal sectional view of the eleventh structure of the back contact battery provided by the embodiment of the present application;

[0047] Figure 17 It is the SEM at a partial first boundary in the back contact battery provided by the embodiment of the present application Figure 1 ;

[0048] Figure 18 SEM at a partial first boundary in the back contact battery provided by the embodiment of the present application Figure 2 ;

[0049] Figure 19 SEM image at a partial second boundary in the back contact battery provided by the embodiment of the present application;

[0050] Figure 20 Longitudinal sectional schematic diagram of the twelfth structure of the back contact battery provided by the embodiment of the present application;

[0051] Figure 21 Longitudinal sectional schematic diagram of the thirteenth structure of the back contact battery provided by the embodiment of the present application;

[0052] Figure 22 Longitudinal sectional schematic diagram of the fourteenth structure of the back contact battery provided by the embodiment of the present application;

[0053] Figure 23 Longitudinal sectional schematic diagram of the fifteenth structure of the back contact battery provided by the embodiment of the present application;

[0054] Figure 24 Longitudinal sectional schematic diagram of the sixteenth structure of the back contact battery provided by the embodiment of the present application;

[0055] Figure 25 Longitudinal sectional schematic diagram of the seventeenth structure of the back contact battery provided by the embodiment of the present application;

[0056] Figure 26 Longitudinal sectional schematic diagram of the eighteenth structure of the back contact battery provided by the embodiment of the present application;

[0057] Figure 27 Longitudinal sectional schematic diagram of the nineteenth structure of the back contact battery provided by the embodiment of the present application;

[0058] Figure 28 Longitudinal sectional schematic diagram of the twentieth structure of the back contact battery provided by the embodiment of the present application.

[0059] Reference numerals: 11 is a semiconductor substrate, 12 is a first doped semiconductor layer, 13 is a second doped semiconductor layer, 14 is an island-shaped passivation structure, 15 is a first region, 16 is a second region, 17 is a dot-shaped passivation portion, 18 is a strip-shaped doped region, 19 is a connecting doped region, 20 is a first interface passivation layer, 21 is a second interface passivation layer, 22 is a first doped silicon glass layer, 23 is a second doped silicon glass layer, 24 is a spacer region, 25 is a groove structure, 26 is a first sidewall, 27 is a second sidewall, 28 is a first boundary, 29 is a second boundary, 30 is a platform region, 31 is a plane, 32 is a third sidewall, 33 is a first sub-boundary, 34 is a second sub-boundary. Detailed implementation manners

[0060] 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.

[0061] Various structural schematic diagrams according to embodiments of the present application are shown in the accompanying drawings. These figures are not drawn to scale, where certain details are enlarged for clearer expression 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.

[0062] In the context of the present application, when a layer / component is referred to as being "on" another layer / component, the layer / component can be directly on the other layer / component, or there can 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 can be "under" the other layer / component. To make the technical problems, technical solutions, and beneficial effects to be solved by the present application clearer and more understandable, 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.

[0063] Furthermore, the terms "first" and "second" are only used for descriptive purposes and cannot be construed 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 clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0064] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it 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 a direct connection or an indirect connection 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.

[0065] 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. Among them, a back-contact cell is a solar cell in which both the positive electrode and the negative electrode are located on the back surface of the cell. Compared with a double-sided contact solar cell, the front surface of this back-contact cell has no metal electrode blocking, so that the light-receiving side of the back-contact cell has a higher light utilization rate. Therefore, the back-contact cell has a higher short-circuit current and photoelectric conversion efficiency, and is one of the technical directions for realizing high-efficiency crystalline silicon cells at present.

[0066] However, in order to improve the formation quality and field passivation effect of the doped semiconductor layer on the back side of the cell, the back surface of the existing back-contact cell is provided with a relatively flat surface. And the light trapping effect of the flat surface is poor, resulting in a low utilization rate of the incident light on the back surface of the cell, which is not conducive to improving the bifaciality of the back-contact cell.

[0067] To solve the above technical problems, in a first aspect, an embodiment of the present application provides a back-contact cell. As Figures 1 to 3 shown, the back-contact cell includes: a semiconductor substrate 11, a first doped semiconductor layer 12, a second doped semiconductor layer 13, and an island-shaped passivation structure 14. The semiconductor substrate 11 has opposite first and second surfaces. The first surface includes alternately distributed first regions 15 and second regions 16. The first doped semiconductor layer 12 is disposed on the first regions 15. The second doped semiconductor layer 13 is disposed on the second regions 16. The second doped semiconductor layer 13 and the first doped semiconductor layer 12 have opposite conductivity types. The island-shaped passivation structure 14 is disposed on the side of the first doped semiconductor layer 12 and / or the second doped semiconductor layer 13 facing away from the semiconductor substrate 11, and / or, the island-shaped passivation structure 14 is disposed between the first doped semiconductor layer 12 and / or the second doped semiconductor layer 13 and the semiconductor substrate 11.

[0068] When the back-contact battery is in the working state, the first doped semiconductor layer and the second doped semiconductor layer can effectively shunt and collect carriers, which is conducive to the formation of photocurrent. The island-shaped passivation structure 14 provided in the back-contact battery has a passivation function on the one hand. It can passivate the surface of the area where the island-shaped passivation structure 14 is formed, reduce the number of defects on the area surface, and reduce the carrier recombination rate. On the other hand, it can change the transmission path of the incident light (such as increasing the reflection path of the incident light), which is beneficial to more incident light refracting into the battery, improving the absorption ratio of the incident light, and improving the bifaciality of the back-contact battery. For example, Figures 1 to 3 As shown, taking the case where the island-shaped passivation structure 14 is disposed on the side of the first doped semiconductor layer 12 away from the semiconductor substrate 11 as an example for illustration: The island-shaped passivation structure 14 has a passivation function and can strengthen the passivation of the surface of the area where the island-shaped passivation structure 14 is formed. In addition, the island-shaped passivation structure 14 does not belong to a part of the first doped semiconductor layer 12. It is a passivation structure that is additionally disposed on the side of the first doped semiconductor layer 12 away from the semiconductor substrate 11 and has an island shape. There may be a certain height difference between the island-shaped passivation structure 14 and the side of the first doped semiconductor layer 12 away from the semiconductor substrate 11, or there are material differences between the island-shaped passivation structure 14 and the first doped semiconductor layer, so that the side surface of the island-shaped passivation structure 14 can reflect or refract the incident light on one side of the first surface of the back-contact battery, change the transmission path of the incident light (such as increasing the reflection path of the incident light), which is beneficial to more incident light refracting into the battery, improving the absorption ratio of the incident light, and improving the bifaciality of the back-contact battery. It should be noted that, Figure 3 the black elliptical contour line in

[0069] is a line drawn to show the approximate position of the island-shaped passivation structure 14 and does not belong to a part of the battery structure. Figure 2 As shown, when the island-shaped passivation structure 14 is disposed on the side of the second doped semiconductor layer 13 away from the semiconductor substrate 11, the island-shaped passivation structure 14 does not belong to a part of the second doped semiconductor layer 13 and is a passivation structure additionally disposed outside the second doped semiconductor layer. As Figure 2 shown, when the island-shaped passivation structure 14 is disposed between the first doped semiconductor layer 12 and the semiconductor substrate 11, the island-shaped passivation structure 14 neither belongs to the first doped semiconductor layer 12 nor belongs to the semiconductor substrate 11 and is a passivation structure additionally disposed outside the second doped semiconductor layer. As Figure 1 and Figure 2As shown, when the island-shaped passivation structure 14 is disposed between the second doped semiconductor layer 13 and the semiconductor substrate 11, the island-shaped passivation structure 14 neither belongs to the second doped semiconductor layer 13 nor the semiconductor substrate 11, and is a passivation structure additionally disposed outside the second doped semiconductor layer.

[0070] In the actual application process, the embodiments of the present application do not specifically limit the material and conductivity type of the semiconductor substrate. Exemplarily, the semiconductor substrate may be a silicon substrate. Alternatively, the semiconductor substrate may also be a substrate of any semiconductor material such as a silicon-germanium substrate, a germanium substrate, or a gallium arsenide substrate. Secondly, the semiconductor substrate may be an N-type semiconductor substrate, a P-type semiconductor substrate, or an intrinsic semiconductor substrate.

[0071] The 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. Among them, the distribution of the first region and the second region on the first surface can be determined according to the distribution of the first doped semiconductor layer and the second doped semiconductor layer formed on the first surface. Specifically, since the first doped semiconductor layer included in the back contact battery is disposed on the first region, the distribution range of the first region on the first surface can be determined according to the distribution requirements of the first doped semiconductor layer in the actual application scenario. Since the second doped semiconductor layer included in the back contact battery is disposed on the second region of the first surface, the distribution range of the second region on the first surface can be determined according to the distribution requirements of the second doped semiconductor layer on the semiconductor substrate in the actual application scenario.

[0072] It can be understood that one of the first region and the second region roughly corresponds to the emitter region, and the other roughly corresponds to the back field region. In terms of the specific conductivity type, one of the first region and the second region roughly corresponds to the P region, and the other roughly corresponds to the N region.

[0073] As for the shapes of the first region and the second region, they can be set according to actual needs as long as they can be applied to the back contact battery provided by the embodiments of the present application. For example: the first region and the second region may be alternately distributed in a strip shape or alternately distributed in an interdigitated shape.

[0074] In terms of the surface topography, as Figure 1 and Figure 2 shown, the second surface of the semiconductor substrate 11 may be a polished surface. Alternatively, as Figure 4 shown, the second surface of the semiconductor substrate 11 may also be a textured surface to improve the light trapping effect of the second surface and improve the light utilization rate of the semiconductor substrate 11.

[0075] As for the topography of the first surface of the semiconductor substrate, as Figure 4As shown, the surfaces of the first region 15 and the second region 16 can be flat surfaces to improve the formation quality of the first doped semiconductor layer 12 and the second doped semiconductor layer 13 and enhance the field passivation effect of the first doped semiconductor layer 12 and the second doped semiconductor layer 13.

[0076] For the first doped semiconductor layer and the second doped semiconductor layer, in terms of the conduction type, the embodiments of the present application do not specifically limit the conduction types of the first doped semiconductor layer and the second doped semiconductor layer, as long as the conduction types of the first doped semiconductor layer and the second doped semiconductor layer are opposite. Specifically, the conduction type of the first doped semiconductor layer can be N-type, and the conduction type of the second doped semiconductor layer is P-type. Alternatively, the conduction type of the first doped semiconductor layer can also be P-type, and the conduction type of the second doped semiconductor layer is N-type.

[0077] In terms of materials, the materials of the first doped semiconductor layer and / or the second 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 phases of the first doped semiconductor layer and / or the second doped semiconductor layer can be amorphous, microcrystalline, nanocrystalline, single crystal, or polycrystalline, etc.

[0078] The materials of the first doped semiconductor layer and the second doped semiconductor layer can be the same or different. For example: the materials of the first doped semiconductor layer and the second doped semiconductor layer can both be doped polysilicon or doped amorphous silicon. Another example: the material of one of the first doped semiconductor layer and the second doped semiconductor layer is doped polysilicon, and the material of the other is doped amorphous silicon.

[0079] In terms of the distribution range, as Figure 1 and Figure 4 shown, along the direction parallel to the first surface, the first doped semiconductor layer 12 and the second doped semiconductor layer 13 can be spaced apart. In this case, the first surface of the semiconductor substrate 11 further includes a spacer region 24 located between the first region 15 and the second region 16. The surface of the spacer region 24 can be flat or textured.

[0080] Or, as Figure 5 shown, at least part of the first doped semiconductor layer 12 and at least part of the second doped semiconductor layer 13 can also be adjacent. In this case, the adjacent part of the first doped semiconductor layer 12 and the second doped semiconductor layer 13 can form a diode structure with a lower reverse breakdown voltage to reduce the hot spot risk when the back contact cell is shaded and improve the anti-burning ability of the back contact cell. The embodiments of the present application do not specifically limit the setting range of the adjacent part of the first doped semiconductor layer 12 and the second doped semiconductor layer 13, which can be determined according to the requirements for the hot spot risk and conversion efficiency of the back contact cell in the actual application scenario.

[0081] Alternatively, as Figure 6 and Figure 7 shown, at least a part of the second doped semiconductor layer 13 is not only disposed on the second region 16, but also extends to cover a part of the first doped semiconductor layer 12. In this case, within the first region 15, as Figure 6 shown, the second doped semiconductor layer 13 can be in direct contact with the first doped semiconductor layer 12 to form a diode structure with a lower reverse breakdown voltage, reducing the hot spot risk when the back contact cell is shaded; or, as Figure 7 shown, an insulating layer can also be disposed between the second doped semiconductor layer 13 and the first doped semiconductor layer 12 to electrically isolate the first doped semiconductor layer 12 and the second doped semiconductor layer 13. The material of the insulating layer can include any one of insulating materials such as silicon oxide, silicon nitride, aluminum oxide or silicon oxynitride, as long as it can be applied to the back contact cell provided in the embodiments of the present application. In addition, within the first region 15, the width of the second doped semiconductor layer 13 overlapping the first doped semiconductor layer 12 can be set according to actual needs, and no specific limitation is made here.

[0082] In terms of the formation position, as Figures 4 to 7 shown, the first doped semiconductor layer 12 can be directly disposed on the first region 15. Or, as Figure 8 shown, the back contact cell can also include a first interface passivation layer 20 located between the first doped semiconductor layer 12 and the semiconductor substrate 11. In this case, the passivation contact structure composed of the first interface passivation layer 20 and the first doped semiconductor layer 12 has excellent interface passivation effect, and can achieve selective collection of carriers, reducing the carrier recombination rate in the first region 15 on the first surface of the semiconductor substrate 11, and further improving the photoelectric conversion efficiency of the back contact cell. The material and thickness of the first interface passivation layer 20 can be set according to the material of the first doped semiconductor layer 12 and actual needs, and no specific limitation is made here. For example: when the material of the first doped semiconductor layer is doped polysilicon, the first interface passivation layer is a tunneling passivation layer. Another example: when the material of the first doped semiconductor layer includes at least one of doped amorphous silicon, doped microcrystalline silicon and doped nanocrystalline silicon, the first interface passivation layer is an intrinsic amorphous silicon layer, an intrinsic microcrystalline silicon layer, an intrinsic nanocrystalline silicon layer or a mixture of the above three.

[0083] As for the second doped semiconductor layer, the second doped semiconductor layer can be directly disposed on the second region. Or, as Figure 8 and Figure 9 shown, the back contact cell can also include a second interface passivation layer 21 located between the second doped semiconductor layer 13 and the semiconductor substrate 11. (As Figure 9As shown, when at least part of the second doped semiconductor layer 13 also extends to cover part of the first doped semiconductor layer 12, the second interface passivation layer 21 also extends from the second region 16 to between the first doped semiconductor layer 12 and the second doped semiconductor layer 13). In this case, the passivation contact structure composed of the second interface passivation layer 21 and the second doped semiconductor layer 13 has an excellent interface passivation effect, and can achieve selective collection of carriers, reduce the carrier recombination rate of the second region 16 of the first surface of the semiconductor substrate 11, and further improve the photoelectric conversion efficiency of the back contact battery. The setting principle of the material and thickness of the second interface passivation layer 21 can refer to the setting principle of the material and thickness of the first interface passivation layer 20 described above, and will not be repeated here.

[0084] For the island passivation structure, from the morphology point of view, such as Figure 10 As shown, at least one island-like passivation structure 14 may include a plurality of point-like passivation portions 17 that are not adjacent to each other and are distributed in a clustered manner. This is beneficial to increase the specific surface area of ​​a single island-like passivation structure 14, increase the light absorption area of ​​a single island-like passivation structure 14, enhance the light trapping effect of the island-like passivation structure 14, and further improve the incident light absorption ratio and the bifaciality of the back-contact battery. In this case, the number of point-like passivation portions 17 included in a single island-like passivation structure 14, as well as the distribution and morphology of different point-like passivation portions 17 can be set according to actual needs. The point-like passivation portion 17 may be a roughly regular hemispherical, circular / pyramidal, circular / prismoid, circular / prismatic or mountain-like morphology, or may be an irregular shape with an uneven surface. It should be noted that Figure 10 The black elliptical outline in FIG. 1 is a line drawn to show the approximate position of the island-shaped passivation structure 14 and is not part of the battery structure.

[0085] Alternatively, if Figure 3As shown, at least one island-shaped passivation structure 14 can also be an integral structure with continuously distributed different regions of itself. Another example can be provided for the morphology of the island-shaped passivation structure 14, which improves the applicability of the back-contact battery provided by the embodiments of the present application in different application scenarios and reduces the process difficulty of manufacturing the back-contact battery. In this case, the island-shaped passivation structure 14 can have a relatively flat surface (at this time, the morphology of the island-shaped passivation structure 14 can refer to the morphology of the regularly shaped dot-shaped passivation part described above); optionally, the surface of the island-shaped passivation structure 14 can also have a undulating morphology, and the protruding or recessed direction, position, and size of the undulating morphology can be set according to actual needs and will not be specifically limited here. The application principle of the beneficial effects when different regions of at least one island-shaped passivation structure 14 are continuously distributed and the surface of the island-shaped passivation structure 14 has a undulating morphology can refer to the application principle of the beneficial effects of the island-shaped passivation structure 14 including a plurality of dot-shaped passivation parts that are not adjacent to each other and are distributed in an aggregated manner described above.

[0086] Optionally, the edge of at least one island-shaped passivation structure can be in a substantially regular shape. For example: when the island-shaped passivation structure is semi-spherical, the edge of the island-shaped passivation structure is circular. Another example: when the island-shaped passivation structure is pyramid-like, the edge of the island-shaped passivation structure is polygon-like. Or, as Figure 3 and Figure 10 shown, the edge of at least one island-shaped passivation structure 14 is in an irregular shape, which is beneficial for the island-shaped passivation structure 14 to have side surfaces arranged in different directions, so that light incident from different directions can be reflected or refracted, which is beneficial for more incident light to be refracted into the battery, further improving the incident light absorption ratio and the bifaciality of the back-contact battery. In this case, the specific morphology of the irregular-shaped edge of the island-shaped passivation structure 14 can be determined according to the three-dimensional morphology of the island-shaped passivation structure 14 described above and will not be specifically limited here.

[0087] It should be noted that when the island-shaped passivation structure includes a plurality of dot-shaped passivation parts that are not adjacent to each other and are distributed in an aggregated manner, the edge of the island-shaped passivation structure refers to the edge of the region occupied by the plurality of dot-shaped passivation parts that are not adjacent to each other and are distributed in an aggregated manner as a whole. When different regions of the island-shaped passivation structure are continuously distributed, the edge of the island-shaped passivation structure refers to the edge surrounded by the continuously distributed different regions.

[0088] In terms of distribution, the island-shaped passivation structures included in the back-contact battery can be randomly distributed. Optionally, as Figure 3 and Figure 10As shown, at least part of the island-shaped passivation structure 14 can be regularly distributed. In this case, the distribution pattern can be set according to the interaction characteristics between the incident light and the island-shaped passivation structure 14, to regularly reflect or refract the incident light on one side of the first surface of the back-contact battery, and be used in combination with the self-irregular light trapping of the island-shaped passivation structure, to maximize the utilization of the incident light, and is also conducive to further improving the self-light trapping effect of the island-shaped passivation structure 14. Or because there is an island-shaped passivation structure 14 between the first doped semiconductor layer 12 and / or the second doped semiconductor layer 13 and the semiconductor substrate 11, the side of the first doped semiconductor layer 12 and / or the second doped semiconductor layer 13 facing away from the semiconductor substrate 11 has a high light trapping effect, reducing the light shielding effect, and further increasing the incident light absorption ratio and the bifaciality of the back-contact battery.

[0089] In the actual application process, in a back-contact battery, which island-shaped passivation structures are regularly distributed can be determined according to the light trapping requirements of different regions on the back side of the battery, and no specific limitation is made here. For example Figure 3 and Figure 10 as shown, it can be that different island-shaped passivation structures 14 provided on the side of the first doped semiconductor layer 12 and / or the second doped semiconductor layer 13 facing away from the semiconductor substrate 11 are regularly distributed; it can also be that different island-shaped passivation structures 14 provided between the first doped semiconductor layer 12 and / or the second doped semiconductor layer 13 and the semiconductor substrate 11 can be regularly distributed; it can also be that all the island-shaped passivation structures 14 included in the back-contact battery are regularly distributed.

[0090] At least part of the island-shaped passivation structures being regularly distributed means that different island-shaped passivation structures in this part of the island-shaped passivation structures are distributed in a regular pattern. For example: different island-shaped passivation structures are distributed along a fixed direction (such as being distributed in a matrix or concentric circles, etc.). Another example: different island-shaped passivation structures are distributed at approximately the same spacing. Another example: different island-shaped passivation structures are distributed in approximately the same pattern morphology.

[0091] In addition, it should be noted that, as Figures 11 to 13 shown, the first doped semiconductor layer 12 and the second doped semiconductor layer 13 can both include strip-shaped doping regions 18. And, the strip-shaped doping regions 18 included in the first doped semiconductor layer 12 and the strip-shaped doping regions 18 included in the second doped semiconductor layer 13 both extend along the first direction and are alternately spaced along the second direction; the first direction is different from the second direction. In the above case, at least part of the island-shaped passivation structures 14 included in the back-contact battery are distributed between the strip-shaped doping regions 18 and the semiconductor substrate 11, and / or, the island-shaped passivation structures 14 are distributed on the side of the strip-shaped doping regions 18 facing away from the semiconductor substrate 11.

[0092] The specific directions referred to by the first direction and the second direction can be determined according to the morphologies of the first doped semiconductor layer and the second doped semiconductor layer, as well as the first region and the second region, and no specific limitation is made here.

[0093] For example: As Figure 11 shown, when the first doped semiconductor layer 12 and the second doped semiconductor layer 13 are alternately distributed in a strip shape, the first direction refers to the length extension direction of the first doped semiconductor layer 12 and the second doped semiconductor layer 13, and the second direction refers to the width direction of the first doped semiconductor layer 12 and the second doped semiconductor layer 13.

[0094] Another example: As Figure 13 shown, when the first doped semiconductor layer 12 and the second doped semiconductor layer 13 are alternately distributed in an interdigitated shape, the first direction refers to the arrangement direction of the first doped semiconductor layer 12 and the second doped semiconductor layer 13, and the second direction refers to the length extension direction of the first doped semiconductor layer 12 and the second doped semiconductor layer 13.

[0095] Optionally, as Figure 11 shown, the first doped semiconductor layer 12 and the second doped semiconductor layer 13 may only include strip-shaped doping regions 18. Or, as Figure 12 and Figure 13 shown, the first doped semiconductor layer 12 and the second doped semiconductor layer 13 may also both include strip-shaped doping regions 18 and connecting doping regions 19. The connecting doping regions 19 included in the first doped semiconductor layer 12 and the second doped semiconductor layer 13 extend along the second direction and are alternately spaced along the first direction. The connecting doping regions 19 included in the first doped semiconductor layer 12 are connected to at least part of the strip-shaped doping regions 18 included in the first doped semiconductor layer 12. The connecting doping regions 19 included in the second doped semiconductor layer 13 are connected to at least part of the strip-shaped doping regions 18 included in the second doped semiconductor layer 13. Among them, the number of strip-shaped doping regions 18 connected by the connecting doping regions 19 included in the first doped semiconductor layer 12 and the second doped semiconductor layer 13 can be determined according to actual needs and no specific limitation is made here. In this case, the island-shaped passivation structure 14 included in the back contact battery can also be disposed between the connecting doping region 19 and the semiconductor substrate 11, and / or the island-shaped passivation structure 14 is distributed on the side of the connecting doping region 19 facing away from the semiconductor substrate 11.

[0096] Among the different island-shaped passivation structures disposed between the same strip-shaped doping region and the semiconductor substrate, or disposed on the side of the same strip-shaped doping region facing away from the semiconductor substrate, the distance between two adjacent island-shaped passivation structures along the first direction may be equal to the distance between two adjacent island-shaped passivation structures along the second direction. Or, as Figure 3As shown, the spacing between two island-shaped passivation structures 14 adjacent to each other along the first direction may also be smaller than the spacing between two island-shaped passivation structures 14 adjacent to each other along the second direction. It can be understood that the length of the strip-shaped doped region 18 is greater than the width of the strip-shaped doped region 18, and the light trapping requirement along the length direction (i.e., the first direction) of the strip-shaped doped region 18 is greater than the light trapping requirement along the width direction (i.e., the second direction) of the strip-shaped doped region 18. Therefore, the spacings between different pairs of island-shaped passivation structures 14 along the first direction and along the second direction are different, which can meet different light trapping requirements along the first direction and along the second direction, respectively, so that the island-shaped passivation structures 14 adjacent to each other along the first direction have a higher light trapping effect, further improving the bifaciality of the back contact battery.

[0097] The distribution of two island-like passivation structures adjacent to each other along different directions in different island-like passivation structures arranged between the same connecting doping region and the semiconductor substrate, or arranged on the side of the same connecting doping region away from the semiconductor substrate can refer to the distribution of two island-like passivation structures adjacent to each other along different directions in different island-like passivation structures arranged between the same strip-like doping region and the semiconductor substrate, or arranged on the side of the same strip-like doping region away from the semiconductor substrate in the previous article, which will not be repeated here.

[0098] As for the specific spacing between two adjacent island-shaped passivation structures, it can be determined based on the passivation effect of the island-shaped passivation structure and the light trapping requirements of the island-shaped passivation structure in the actual application scenario, and is not specifically limited here.

[0099] Exemplarily, the distance between two adjacent island-shaped passivation structures can be greater than or equal to 40 μm and less than or equal to 300 μm. For example, the distance between two adjacent island-shaped passivation structures can be 40 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, etc. By setting the distance between two adjacent island-shaped passivation structures within the above range, it is possible to prevent the distribution density of the island-shaped passivation structures provided on the semiconductor substrate from being too high due to the small distance between two adjacent island-shaped passivation structures, which may affect the formation quality of the first doped semiconductor layer and / or the second doped semiconductor layer on the island-shaped passivation structures. Alternatively, when the island-shaped passivation structure includes a doped semiconductor passivation portion and the conduction type of the doped semiconductor passivation portion is opposite to that of the first doped semiconductor layer or the second doped semiconductor layer adjacent to itself, it is possible to prevent a relatively high leakage risk between the island-shaped passivation structure and the first doped semiconductor layer or the second doped semiconductor layer due to the small distance between two adjacent island-shaped passivation structures. By controlling the distance between two adjacent island-shaped passivation structures, the distribution density of the island-shaped passivation structures is controlled to ensure that the carrier recombination rate is within a controllable range. In addition, it is also possible to prevent poor light trapping effect on one side of the first surface of the back contact battery due to the large distance between two adjacent island-shaped passivation structures, which is beneficial to achieving a relatively high incident light absorption ratio on one side of the first surface and further improving the bifaciality of the back contact battery.

[0100] Optionally, along the first direction, the distance between two adjacent island-shaped passivation structures can be greater than or equal to 40 μm and less than or equal to 200 μm.

[0101] Optionally, along the second direction, the distance between two adjacent island-shaped passivation structures can be greater than or equal to 40 μm and less than or equal to 300 μm.

[0102] In terms of size, the embodiments of the present application do not specifically limit the size of the island-shaped passivation structure, which can be determined according to the passivation effect requirements for the island-shaped passivation structure and the light trapping requirements for the island-shaped passivation structure in the actual application scenario.

[0103] When at least one island-shaped passivation structure is disposed between the first doped semiconductor layer and / or the second doped semiconductor layer and the semiconductor substrate, and the surfaces of the first region and the second region of the semiconductor substrate further have a tower-base-like structure that is recessed in a direction close to the semiconductor substrate, or when at least one island-shaped passivation structure is disposed on a side of the first doped semiconductor layer and / or the second doped semiconductor layer facing away from the semiconductor substrate, and the side of the first doped semiconductor layer and the second doped semiconductor layer facing away from the semiconductor substrate further has a tower-base-like structure that is recessed in a direction close to the semiconductor substrate, at least one island-shaped passivation structure can be disposed within the tower-base-like structure. In this case, the surface of the island-shaped passivation structure and the surface of the tower-base-like structure can cooperate with each other to improve the transmission path of incident light, further improving the light utilization rate on the back side of the back contact battery. As for the one-dimensional size of the tower-base-like structure in this case, it can be set according to actual needs and will not be specifically limited here. In addition, in this case, the area ratio of a single island-shaped passivation structure on the bottom surface of the tower-base-like structure can be less than or equal to 40%. This is conducive to controlling the size of the island-shaped passivation structure within a reasonable range, so that there is a certain distance between the side surface of the island-shaped passivation structure and the side surface of the tower-base-like structure, facilitating the reflection or refraction of incident light. In addition, it can also prevent the formation quality of the first doped semiconductor layer and / or the second doped semiconductor layer formed on the island-shaped passivation structure from being affected due to the excessive area occupied by the island-shaped passivation structure. Or when the island-shaped passivation structure includes a doped semiconductor passivation part and the doped semiconductor passivation part has a conductivity type opposite to that of the adjacent first doped semiconductor layer or second doped semiconductor layer, it can prevent the leakage risk of the battery from increasing due to the excessive area occupied by the island-shaped passivation structure, reduce the carrier recombination rate, and improve the working performance of the back contact battery.

[0104] As for the specific size of the island-shaped passivation structure, exemplarily, the area occupied by at least one island-shaped passivation structure can be greater than or equal to 1 μm 2 and less than or equal to 100 μm 2 . For example: the area occupied by at least one island-shaped passivation structure can be greater than or equal to 1 μm 2 , 10 μm 2 , 20 μm 2 , 30 μm 2 , 50 μm 2 , 80 μm 2 or 100 μm 2etc. The area occupied by at least one island-shaped passivation structure within the above range is conducive to preventing the passivation effect of the island-shaped passivation structure from being low due to the too small area occupied by the island-shaped passivation structure, and the degree of the light trapping effect of the island-shaped passivation structure itself or improved due to the setting of the island-shaped passivation structure is low, which is beneficial to making the back-contact battery have a high bifaciality. In addition, it can also prevent the area occupied by the island-shaped passivation structure from being too large (wherein, the beneficial effect of preventing the area occupied by the island-shaped passivation structure from being too large can refer to the previous text and will not be elaborated here).

[0105] It should be noted that when the island-shaped passivation structure includes a plurality of dot-shaped passivation parts that are not adjacent to each other and are distributed in an aggregated manner, the area occupied by the island-shaped passivation structure refers to the area of the region occupied by the plurality of dot-shaped passivation parts that are not adjacent to each other and are distributed in an aggregated manner as a whole. When different regions of the island-shaped passivation structure are continuously distributed, the area occupied by the island-shaped passivation structure refers to the area enclosed by the continuously distributed different regions.

[0106] In terms of structure, the island-shaped passivation structure can be only a single-layer structure or a laminated structure composed of different layers. As for the material of the island-shaped passivation structure, it can be any material with a passivation effect as long as it can be applied to the back-contact battery provided in the embodiments of the present application.

[0107] Exemplarily, at least one island-shaped passivation structure can include a doped semiconductor passivation part; and / or, at least one island-shaped passivation structure includes an interface passivation part; and / or, at least one island-shaped passivation structure includes a doped semiconductor passivation part and a doped silicon glass part provided on the side of the doped semiconductor passivation part facing away from the semiconductor substrate. It can be seen that the island-shaped passivation structure can be formed by manufacturing at least the doped semiconductor passivation part, the interface passivation part, and the doped silicon glass part, which have good effects and are compatible with the battery manufacturing process. While making the island-shaped passivation structure have a good passivation effect, it can also improve the yield of the back-contact battery. Different materials have different characteristics in terms of light absorption, light reflection, light refraction, etc. By combining different materials, the change of the light path can be realized and the light utilization rate can be improved. In addition, the doped semiconductor passivation part, the interface passivation part, and the doped silicon glass part are also materials for manufacturing the back-contact battery. At this time, the manufacturing of the island-shaped passivation structure can be realized while manufacturing the corresponding structures in the back-contact battery, improving the manufacturing efficiency of the back-contact battery and simplifying the manufacturing process of the back-contact battery.

[0108] It should be noted that the island-shaped passivation structure may only include a doped semiconductor passivation part, or may only include an interface passivation part, or the island-shaped passivation structure may only include an interface passivation part and a doped semiconductor passivation part (in this case, the doped semiconductor passivation part may be disposed on a side of the interface passivation part away from the semiconductor substrate), or the island-shaped passivation structure may only include a doped semiconductor passivation part and a doped silicon glass part, or the island-shaped passivation structure may simultaneously include an interface passivation part, a doped semiconductor passivation part, and a doped silicon glass part (in this case, the interface passivation part, the doped semiconductor passivation part, and the doped silicon glass part may be sequentially stacked in a direction away from the semiconductor substrate).

[0109] The materials, thicknesses of the doped semiconductor passivation part, the interface passivation part, and the doped silicon glass part included in the island-shaped passivation structure, and the conduction types of the doped semiconductor passivation part and the doped silicon glass part may be determined according to actual requirements and are not specifically limited herein.

[0110] Exemplarily, in at least one island-shaped passivation structure disposed on a side of the first doped semiconductor layer away from the semiconductor substrate, or in at least one island-shaped passivation structure disposed between the first doped semiconductor layer and the semiconductor substrate, the material and conduction type of the doped semiconductor passivation part may be the same as the material and conduction type of the second doped semiconductor layer, respectively.

[0111] Exemplarily, in at least one island-shaped passivation structure disposed on a side of the first doped semiconductor layer away from the semiconductor substrate, or in at least one island-shaped passivation structure disposed between the first doped semiconductor layer and the semiconductor substrate, the thickness of the doped semiconductor passivation part may be less than or equal to the thickness of the second doped semiconductor layer.

[0112] Exemplarily, in at least one island-shaped passivation structure disposed on a side of the second doped semiconductor layer away from the semiconductor substrate, or in at least one island-shaped passivation structure disposed between the second doped semiconductor layer and the semiconductor substrate, the material and conduction type of the doped semiconductor passivation part may be the same as the material and conduction type of the first doped semiconductor layer, respectively.

[0113] Exemplarily, in at least one island-shaped passivation structure disposed on a side of the second doped semiconductor layer away from the semiconductor substrate, or in at least one island-shaped passivation structure disposed between the second doped semiconductor layer and the semiconductor substrate, the thickness of the doped semiconductor passivation part may be less than or equal to the thickness of the first doped semiconductor layer.

[0114] It should be noted that, taking the example where the material and conductivity type of the doped semiconductor passivation part of the island-shaped passivation structure adjacent to the first doped semiconductor layer are the same as those of the second doped semiconductor layer respectively: The manufacturing of the doped semiconductor passivation part of the island-shaped passivation structure adjacent to the first doped semiconductor layer can be achieved simultaneously with the manufacturing of the second doped semiconductor layer, improving the manufacturing efficiency of the back-contact battery and simplifying the manufacturing process of the back-contact battery.

[0115] Of course, the material and / or conductivity type of the doped semiconductor passivation part of the island-shaped passivation structure adjacent to the first doped semiconductor layer can also be different from those of the second doped semiconductor layer respectively. In this case, the doped semiconductor passivation part of the island-shaped passivation structure adjacent to the first doped semiconductor layer and the second doped semiconductor layer can be manufactured separately. The material and / or conductivity type of the doped semiconductor passivation part of the island-shaped passivation structure adjacent to the second doped semiconductor layer can also be different from those of the first doped semiconductor layer respectively.

[0116] Regarding the interface passivation part included in at least one island-shaped passivation structure, as described above, when the back-contact battery further includes a first interface passivation layer, among the at least one island-shaped passivation structure disposed on the side of the first doped semiconductor layer away from the semiconductor substrate, or among the at least one island-shaped passivation structure disposed between the first doped semiconductor layer and the semiconductor substrate, the material of the interface passivation part can be the same as that of the second interface passivation layer. This is beneficial to improving the manufacturing efficiency of the back-contact battery and simplifying the manufacturing process of the back-contact battery.

[0117] Exemplarily, among the at least one island-shaped passivation structure disposed on the side of the first doped semiconductor layer away from the semiconductor substrate, or among the at least one island-shaped passivation structure disposed between the first doped semiconductor layer and the semiconductor substrate, the thickness of the interface passivation part can be less than or equal to the thickness of the second interface passivation layer.

[0118] When the back-contact battery further includes a second interface passivation layer, among the at least one island-shaped passivation structure disposed on the side of the second doped semiconductor layer away from the semiconductor substrate, or among the at least one island-shaped passivation structure disposed between the second doped semiconductor layer and the semiconductor substrate, the material of the interface passivation part is the same as that of the first interface passivation layer. This is beneficial to improving the manufacturing efficiency of the back-contact battery and simplifying the manufacturing process of the back-contact battery.

[0119] Exemplarily, among the at least one island-shaped passivation structure disposed on the side of the second doped semiconductor layer away from the semiconductor substrate, or among the at least one island-shaped passivation structure disposed between the second doped semiconductor layer and the semiconductor substrate, the thickness of the interface passivation part is less than or equal to the thickness of the first interface passivation layer.

[0120] Of course, the material of the interface passivation portion included in the island-shaped passivation structure adjacent to the first doped semiconductor layer may also be different from the material of the second interface passivation layer. In this case, the interface passivation portion of the island-shaped passivation structure adjacent to the first doped semiconductor layer and the second interface passivation layer may be manufactured separately. The material of the interface passivation portion of the island-shaped passivation structure adjacent to the second doped semiconductor layer may also be different from the material of the first interface passivation layer.

[0121] When the back contact cell does not include the first interface passivation layer and / or the second interface passivation layer, the material of the interface passivation portion included in the corresponding island passivation structure may include any interface passivation layer material such as silicon oxide, aluminum oxide and intrinsic silicon.

[0122] As for the doped silicon glass portion included in at least one island-shaped passivation structure, for example, Figure 14 As shown, the back contact cell may also include a first doped silicon glass layer 22 disposed on the side of the first doped semiconductor layer 12 away from the semiconductor substrate 11, and the first doped silicon glass layer 22 has the same conductivity type as the first doped semiconductor layer 12. The first doped semiconductor layer 12 is passivated on the side away from the semiconductor substrate 11, and is used to prevent the first doped semiconductor layer 12 from being affected when the second doped semiconductor layer 13 is manufactured, which is beneficial for the first doped semiconductor layer 12 to have a higher retention, diversion and collection capacity. The embodiment of the present application does not specifically limit the doping concentration and thickness of the impurities in the first doped silicon glass layer 22. In this case, in at least one island-shaped passivation structure 14 disposed on the side of the second doped semiconductor layer 13 away from the semiconductor substrate 11, or in at least one island-shaped passivation structure 14 disposed between the second doped semiconductor layer 13 and the semiconductor substrate 11, the material and conductivity type of the doped silicon glass part are respectively the same as the material and conductivity type of the first doped silicon glass layer 22. The manufacturing efficiency of the back contact cell is improved and the manufacturing process of the back contact cell is simplified.

[0123] Exemplarily, in at least one island-shaped passivation structure disposed on a side of the second doped semiconductor layer facing away from the semiconductor substrate, or in at least one island-shaped passivation structure disposed between the second doped semiconductor layer and the semiconductor substrate, the thickness of the doped silicon glass portion is less than or equal to the thickness of the first doped silicon glass layer.

[0124] For example, Figure 14As shown, the back-contact battery may further include a second doped silicon glass layer 23 disposed on the side of the second doped semiconductor layer 13 away from the semiconductor substrate 11. The second doped silicon glass layer 23 has the same conductivity type as the second doped semiconductor layer 13 to passivate the side of the second doped semiconductor layer 13 away from the semiconductor substrate 11. The embodiments of the present application do not specifically limit the doping concentration and thickness of the impurities in the second doped silicon glass layer 23. In this case, among at least one island-shaped passivation structure 14 disposed on the side of the first doped semiconductor layer 12 away from the semiconductor substrate 11, or at least one island-shaped passivation structure 14 disposed between the first doped semiconductor layer 12 and the semiconductor substrate 11, the material and conductivity type of the doped silicon glass portion may be the same as those of the second doped silicon glass layer 23 respectively. This can improve the manufacturing efficiency of the back-contact battery and simplify the manufacturing process of the back-contact battery.

[0125] Exemplarily, among at least one island-shaped passivation structure disposed on the side of the first doped semiconductor layer away from the semiconductor substrate, or at least one island-shaped passivation structure disposed between the first doped semiconductor layer and the semiconductor substrate, the thickness of the doped silicon glass portion may be less than or equal to the thickness of the second doped silicon glass layer.

[0126] Of course, the material and / or conductivity type of the doped silicon glass portion of the island-shaped passivation structure adjacent to the first doped semiconductor layer may also be different from those of the second doped silicon glass layer respectively. In this case, the doped silicon glass portion of the island-shaped passivation structure adjacent to the first doped semiconductor layer and the second doped silicon glass layer can be manufactured separately. The material and / or conductivity type of the doped silicon glass portion of the island-shaped passivation structure adjacent to the second doped semiconductor layer may also be different from those of the first doped silicon glass layer.

[0127] In terms of the formation position, the island-shaped passivation structure included in the back-contact battery may be disposed only on the side of the first doped semiconductor layer away from the semiconductor substrate, may be disposed only on the side of the second doped semiconductor layer away from the semiconductor substrate, may be disposed only between the first doped semiconductor layer and the semiconductor substrate, may be disposed only between the second doped semiconductor layer and the semiconductor substrate, or may be a combination of at least two of the above four cases. The embodiments of the present application do not specifically limit the formation position of the island-shaped passivation structure, which can be determined according to the actual application scenario and the actual manufacturing process.

[0128] Exemplarily, as Figure 1 shown, the island-shaped passivation structure 14 disposed on the first region 15 may be located on the side of the first doped semiconductor layer 12 away from the semiconductor substrate 11, and the island-shaped passivation structure 14 disposed on the second region 16 may be disposed between the second doped semiconductor layer 13 and the semiconductor substrate 11.

[0129] Alternatively, as Figure 15 shown, the island-shaped passivation structure 14 disposed on the first region 15 is located between the first doped semiconductor layer 12 and the semiconductor substrate 11, and the island-shaped passivation structure 14 disposed on the second region 16 is disposed on the side of the second doped semiconductor layer 13 away from the semiconductor substrate 11.

[0130] It should be noted that the first doped semiconductor layer and the second doped semiconductor layer included in the back contact battery are respectively formed on local regions of the first surface in different operation steps. Moreover, in the process of manufacturing the first doped semiconductor layer and the second doped semiconductor layer, the patterned first doped semiconductor layer and the second doped semiconductor layer are obtained by selectively etching the doped semiconductor layer provided for the whole layer. Therefore, taking the example that the island-shaped passivation structure disposed on the first region is located on the side of the first doped semiconductor layer away from the semiconductor substrate, and the island-shaped passivation structure disposed on the second region is disposed between the second doped semiconductor layer and the semiconductor substrate: at this time, the first doped semiconductor layer can be manufactured first, and the island-shaped passivation structure disposed between the second doped semiconductor layer and the semiconductor substrate can be manufactured based on the part of the doped semiconductor material for manufacturing the first doped semiconductor layer located in the second region. Meanwhile, after forming the first doped semiconductor layer and the island-shaped passivation structure disposed on the second region, the second doped semiconductor layer is manufactured, and the island-shaped passivation structure disposed on the side of the first doped semiconductor layer away from the semiconductor substrate is manufactured based on the part of the doped semiconductor material for manufacturing the second doped semiconductor layer located in the first region, which is beneficial to improving the manufacturing efficiency of the back contact battery and simplifying the manufacturing process of the back contact battery.

[0131] It should be noted that, taking the island-shaped passivation structure disposed on the first region and located on the side of the first doped semiconductor layer away from the semiconductor substrate, and the island-shaped passivation structure disposed on the second region and located between the second doped semiconductor layer and the semiconductor substrate as an example for illustration: From a structural perspective, in the island-shaped passivation structure disposed on the side of the first doped semiconductor layer away from the semiconductor substrate, if the back-contact battery does not include the second interface passivation layer and the second doped silicon glass layer, at least one island-shaped passivation structure may only include a doped semiconductor passivation portion, and the material and conductivity type of the doped semiconductor passivation portion may be the same as the material and conductivity type of the second doped semiconductor layer. If the back-contact battery includes the second interface passivation layer, at least one island-shaped passivation structure may only include an interface passivation portion, and the material of the interface passivation portion may be the same as the material of the second interface passivation layer; or, at least one island-shaped passivation structure may include an interface passivation portion and a doped semiconductor passivation portion, the material of the interface passivation portion may be the same as the material of the second interface passivation layer, and the material and conductivity type of the doped semiconductor passivation portion may be the same as the material and conductivity type of the second doped semiconductor layer respectively. Additionally, if the back-contact battery further includes the second doped silicon glass layer, at least one island-shaped passivation structure may only include an interface passivation portion or only include an interface passivation portion and a doped semiconductor passivation portion (when the back-contact battery does not include the second interface passivation layer, only includes the doped semiconductor passivation portion), or, at least one island-shaped passivation structure may include an interface passivation portion, a doped semiconductor passivation portion, and a doped silicon glass portion (when the back-contact battery does not include the second interface passivation layer, includes the doped semiconductor passivation portion and the doped silicon glass portion), and the material and conductivity type of the doped silicon glass portion may be the same as the material and conductivity type of the second doped silicon glass layer. Furthermore, in the island-shaped passivation structure disposed between the second doped semiconductor layer and the semiconductor substrate, if the back-contact battery does not include the first interface passivation layer and the first doped silicon glass layer, at least one island-shaped passivation structure may only include a doped semiconductor passivation portion, and the material and conductivity type of the doped semiconductor passivation portion may be the same as the material and conductivity type of the first doped semiconductor layer. If the back-contact battery includes the first interface passivation layer, at least one island-shaped passivation structure may only include an interface passivation portion, and the material of the interface passivation portion may be the same as the material of the first interface passivation layer; or, at least one island-shaped passivation structure may include an interface passivation portion and a doped semiconductor passivation portion, the material of the interface passivation portion may be the same as the material of the first interface passivation layer, and the material of the doped semiconductor passivation portion may be the same as the material of the first doped semiconductor layer (at this time, the conductivity type of the doped semiconductor passivation portion may be determined according to its own thickness, as well as the material and formation temperature of the second doped semiconductor layer. For example: when the thickness of the doped semiconductor passivation portion is small and the formation temperature of the second doped semiconductor layer is high, due to internal diffusion, the conductivity type of the doped semiconductor passivation portion may be opposite to the conductivity type of the first doped semiconductor layer.In addition, if the back-contact battery further includes a first doped silicon glass layer, at least one island-shaped passivation structure may include only an interface passivation portion or only an interface passivation portion and a doped semiconductor passivation portion (when the back-contact battery does not include a first interface passivation layer, only the doped semiconductor passivation portion), or at least one island-shaped passivation structure may include an interface passivation portion, a doped semiconductor passivation portion, and a doped silicon glass portion (when the back-contact battery does not include a first interface passivation layer, including a doped semiconductor passivation portion and a doped silicon glass portion), and the material of the doped silicon glass portion may be the same as that of the first doped silicon glass layer. (At this time, the conduction type of the doped silicon glass portion can be determined according to its own thickness, as well as the material and formation temperature of the second doped semiconductor layer. For example: when the thickness of the doped silicon glass portion is small and the formation temperature of the second doped semiconductor layer is high, due to internal diffusion, the conduction type of the doped silicon glass portion may be opposite to that of the first doped semiconductor layer.

[0132] It should be noted that this is an example where the island-shaped passivation structure located on the side of the first doped semiconductor layer away from the semiconductor substrate and the corresponding structure provided on the second region are manufactured simultaneously, and the island-shaped passivation structure provided between the second doped semiconductor layer and the semiconductor substrate and the corresponding structure provided on the first region are manufactured simultaneously. When the island-shaped passivation structures are manufactured separately, the specific structure and material of the island-shaped passivation structure can refer to the previous text and will not be elaborated here.

[0133] Regarding the island-shaped passivation structure provided on the first region being located between the first doped semiconductor layer and the semiconductor substrate, and the island-shaped passivation structure provided on the second region being provided on the side of the second doped semiconductor layer away from the semiconductor substrate, the specific situation of the island-shaped passivation structure can refer to the analysis in the previous text of the situation where the island-shaped passivation structure provided on the first region is located on the side of the first doped semiconductor layer away from the semiconductor substrate and the island-shaped passivation structure provided on the second region is provided between the second doped semiconductor layer and the semiconductor substrate, and will not be elaborated here.

[0134] In some examples, such as Figures 16 to 19As shown, when the first surface further includes a spacer region 24 located between the first region 15 and the second region 16, in the direction from the first surface to the second surface, the surface of the spacer region 24 is recessed into the semiconductor substrate 11 relative to the surface of the first region 15 to form a groove structure 25. The groove structure 25 has a first sidewall 26 close to the first region 15 and a second sidewall 27 close to the second region 16. The first doped semiconductor layer 12 has a first boundary 28 close to the spacer region 24. The second doped semiconductor layer 13 has a second boundary 29 close to the spacer region 24. At least one island-shaped passivation structure 14 is at least partially located between the first boundary 28 and the first sidewall 26; and / or, at least one island-shaped passivation structure 14 is at least partially located between the second boundary 29 and the second sidewall 27. To passivate the surface of the region of the semiconductor substrate 11 where the island-shaped passivation structure 14 is formed, reduce the number of defects on the region surface, and reduce the carrier recombination rate. In addition, the island-shaped passivation structure 14 can change the transmission path of incident light (such as increasing the reflection path of incident light), which is beneficial to more incident light refracting into the battery, improving the incident light absorption ratio, and improving the bifaciality of the back contact battery. The island-shaped passivation structure 14 does not belong to a part of the semiconductor substrate 11, and it is an additional passivation structure provided on the semiconductor substrate 11 and having an island shape.

[0135] In terms of surface height, the surface of the spacer region is recessed into the semiconductor substrate relative to the surface of the first region. The depth of the groove structure in the spacer region can be set according to actual needs and will not be specifically limited here. In addition, the first sidewall and the second sidewall of the groove structure can be perpendicularly arranged relative to the groove bottom surface respectively, or can be inclined relative to the groove bottom surface. The first sidewall and the second sidewall can be flat surfaces, or can also be suede surfaces formed with texture structures. When the first sidewall and / or the second sidewall is a suede surface, the types and sizes of the texture structures provided on the first sidewall and / or the second sidewall are not specifically limited in the embodiments of the present application.

[0136] As for the surface of the second region, the surface of the second region can be flush with the surface of the first region; or, as Figure 20 shown, in the direction from the first surface to the second surface, the surface of the second region 16 can also be recessed into the semiconductor substrate 11 relative to the surface of the first region 15 to reduce the residues remaining after the first doped semiconductor layer 12 with more patterning processes on the second region 16, reduce the leakage risk, and be beneficial to improving the formation quality of the second doped semiconductor layer 13. In this case, the surface of the second region 16 can be flush with the surface of the spacer region 24; or, as Figure 20 shown, the surface of the second region 16 can also be higher than the groove bottom surface of the spacer region 24. As for the depth of the surface of the second region 16 recessed into the semiconductor substrate 11, it can be set according to actual needs and will not be specifically limited here.

[0137] In terms of the boundary morphology, the first sidewall included in the defined spacer region has a third boundary, and the second sidewall has a fourth boundary. The morphologies of the third boundary and the fourth boundary can be determined according to the process method used to form the groove structure in the semiconductor substrate in the actual application scenario, and no specific limitation is made here.

[0138] Exemplarily, along the extending direction of the spacer region, the third boundary and / or the fourth boundary can be linear. Or, as Figure 17 and Figure 18 shown, the first sidewall 26 can also be in a third concave-convex alternating structure, and / or, as Figure 19 shown, the second sidewall 27 can also be in a fourth concave-convex alternating structure; the third concave-convex alternating structure and / or the fourth concave-convex alternating structure can be serrated, trapezoidal broken line-shaped, wavy, etc. The third concave-convex alternating structure and / or the fourth concave-convex alternating structure can be a periodic structure with a certain pattern, or an irregular aperiodic structure with microscopic fluctuations and macroscopic rough concave-convex alternation. The sizes of the concave and convex portions in the third concave-convex alternating structure and / or the fourth concave-convex alternating structure along the extending direction and the width direction of the spacer region 24, as well as their morphologies, can be set according to actual requirements, and no specific limitation is made here.

[0139] In terms of the edge morphology, as Figures 16 to 20 shown, along the width direction of the spacer region 24, the morphology of the first boundary 28 of the first doped semiconductor layer 12, and / or, the morphology of the second boundary 29 of the second doped semiconductor layer 13 can be determined according to the process method for manufacturing the first doped semiconductor layer 12 and the second doped semiconductor layer 13, as well as the distribution of the island-shaped passivation structure 14 included in the back contact battery on the semiconductor substrate 11, and no specific limitation is made here.

[0140] Exemplarily, the first boundary and / or the second boundary can be linear. Or, as Figure 17 and Figure 18 shown, the first boundary 28 can also be in a first concave-convex alternating structure, and / or, as Figure 19 shown, the second boundary 29 can also be in a second concave-convex alternating structure; the first concave-convex alternating structure and / or the second concave-convex alternating structure can be serrated, trapezoidal broken line-shaped, wavy, etc. The first concave-convex alternating structure and / or the second concave-convex alternating structure can be a periodic structure with a certain pattern, or an irregular aperiodic structure with microscopic fluctuations and macroscopic rough concave-convex alternation. The sizes of the concave and convex portions in the first concave-convex alternating structure and / or the second concave-convex alternating structure along the extending direction and the width direction of the spacer region 24, as well as their morphologies, can be set according to actual requirements, and no specific limitation is made here.

[0141] When the first sidewall has a third concave-convex alternating structure along the extending direction of the spaced region, the corresponding relationship between the concave and convex portions in the first concave-convex alternating structure and the third concave-convex alternating structure can be determined according to the size of the island-shaped passivation structure and the anti-leakage requirements for the back-contact battery in the actual application scenario, and no specific limitation is made here.

[0142] Exemplarily, as Figure 17 and Figure 18 shown, at least some of the convex portions in the third concave-convex alternating structure are staggered with the adjacent convex portions in the first concave-convex alternating structure. This is beneficial for arranging the island-shaped passivation structure 14 on the portions where the convex or concave portions of the third concave-convex alternating structure are respectively staggered with the concave or convex portions of the first concave-convex alternating structure. While increasing the bifaciality of the battery by arranging the island-shaped passivation structure 14, the first doped semiconductor layer 12 has a large area ratio on the first region 15, enhancing the field passivation effect and carrier collection ability of the first doped semiconductor layer 12. The number and distribution of the convex portions in the third concave-convex alternating structure that are staggered with the adjacent convex portions in the first concave-convex alternating structure can be determined according to the size and distribution of the island-shaped passivation structure 14 located on the first region 15 in the actual application scenario, and no specific limitation is made here. Of course, at least some of the convex portions in the third concave-convex alternating structure can also have the same protruding trend as the adjacent convex portions in the first concave-convex alternating structure.

[0143] Exemplarily, as Figure 19 shown, when the second sidewall 27 has a fourth concave-convex alternating structure, at least some of the convex portions in the fourth concave-convex alternating structure can be staggered with the adjacent convex portions in the second concave-convex alternating structure. The application principle of the beneficial effects in this case can refer to the previous text and will not be elaborated here. The number and distribution of the convex portions in the fourth concave-convex alternating structure that are staggered with the adjacent convex portions in the second concave-convex alternating structure can be determined according to the size and distribution of the island-shaped passivation structure 14 located on the second region 16 in the actual application scenario, and no specific limitation is made here. Of course, at least some of the convex portions in the fourth concave-convex alternating structure can also have the same protruding trend as the adjacent convex portions in the second concave-convex alternating structure.

[0144] In some cases, as Figure 17 and Figure 18 shown, the first boundary 28 can have a first sub-boundary 33 located within the first region 15 and spaced from the first sidewall 26 along the width direction of the spaced region 24, and an island-shaped passivation structure 14 is arranged between at least one first sub-boundary 33 and the first sidewall 26. And / or, as Figure 19 shown, the second boundary 29 has a second sub-boundary 34 located within the second region 16 and spaced from the second sidewall 27 along the width direction of the spaced region 24, and an island-shaped passivation structure 14 is arranged between at least one second sub-boundary 34 and the second sidewall 27.

[0145] As Figure 17 and Figure 18 shown, taking the first sub-boundary 33 where the first boundary 28 is located within the first region 15 and is spaced from the first sidewall 26 of the groove structure 25 in the width direction of the spacer region 24 as an example: When the first boundary 28 further includes the first sub-boundary 33, in the width direction of the spacer region 24, between the portion of the first doped semiconductor layer 12 corresponding to the first sub-boundary 33 and the second doped semiconductor layer 13, there is not only the spacer region 24, but also because the first sub-boundary 33 is spaced from the first sidewall 26 of the groove structure 25. In other words, the portion of the first doped semiconductor layer 12 corresponding to the first sub-boundary 33 is indented into the first region 15 relative to the first sidewall 26 of the groove structure 25. Therefore, the distance between the first doped semiconductor layer 12 and the second doped semiconductor layer 13 can be increased, further reducing the leakage risk between the two. In addition, the island-shaped passivation structure 14 is disposed on the portion of the first region 15 that is not directly covered by the first doped semiconductor layer 12, which can reduce the quality and precision requirements for forming the conductive electrode on the first doped semiconductor layer 12 due to the presence of the island-shaped passivation structure 14. At the same time, the presence of the island-shaped passivation structure 14 can passivate the local surface in the first region 15 of the semiconductor substrate 11 that has a relatively large number of surface defects and a high passivation requirement and is not directly covered by the first doped semiconductor layer 12, which is beneficial to reducing the carrier recombination rate of the local surface and improving the conversion efficiency of the back contact battery.

[0146] The distribution range and position of the first sub-boundary and the second sub-boundary in the first boundary and the second boundary respectively can be determined according to the size and distribution of the island-shaped passivation structures located on the first region and the second region in the actual application scenario, and no specific limitation is made here.

[0147] Exemplarily, as Figure 17 and Figure 18 shown, when the first boundary 28 has a first concave-convex alternating structure, the boundary of at least some of the concave portions in the first concave-convex alternating structure can be the first sub-boundary 33; and / or, as Figure 19 shown, when the second boundary 29 has a second concave-convex alternating structure, the boundary of at least some of the concave portions in the second concave-convex alternating structure can be the second sub-boundary 34.

[0148] Taking the example where the first boundary has a first concave-convex alternating structure and the boundaries of at least some of the concave portions in the first concave-convex alternating structure are first sub-boundaries: The first doped semiconductor layer is disposed opposite to the first sub-boundary within the first region and at least some of the concave portions in the first concave-convex alternating structure, which is conducive to making the concave-convex alternating structure presented by the first boundary more matched with the fluctuation change of the indented part of the first doped semiconductor layer into the first region, can reduce the etching amount of the semiconductor substrate for making the first boundary of the first doped semiconductor layer, is conducive to increasing the light absorption area of the semiconductor substrate, and is conducive to improving the conversion efficiency of the back contact battery.

[0149] In the actual application process, such as Figure 17 and Figure 18 shown, it can be that only the boundaries of some of the concave portions in the first concave-convex alternating structure are the first sub-boundaries 33. In this case, there are some concave portion boundaries aligned with the first sidewall 26 of the groove structure 25, or alternatively, there are some concave portion boundaries in the first concave-convex alternating structure extending above the groove structure 25; of course, it can also be that the boundaries of all the concave portions in the first concave-convex alternating structure are the first sub-boundaries 33.

[0150] Such as Figure 17 and Figure 18 and Figure 25 shown, as for the convex portions in the first concave-convex alternating structure, it can be that only at least some of the convex portions extend above the groove structure along the width direction of the spacer region; or, there are some convex portion boundaries in the first concave-convex alternating structure aligned with the first sidewall 26 of the groove structure; or, there are some convex portion boundaries in the first concave-convex alternating structure located within the first region (i.e., there are some convex portion boundaries that are the first sub-boundaries 33); of course, it can also be that the boundaries of all the convex portions in the first concave-convex alternating structure extend above the groove structure along the width direction of the spacer region.

[0151] When at least a part of the first doped semiconductor layer corresponding to the convex portions is suspended above the groove structure, it is conducive to reflecting part of the light emitted from the first surface of the semiconductor substrate back to the semiconductor substrate and being utilized by the semiconductor substrate again, improving the light utilization rate of the back contact battery.

[0152] As for the second concave-convex alternating structure, such as Figure 19 shown, it can be that only the boundaries of some of the concave portions in the second concave-convex alternating structure are the second sub-boundaries 34. In this case, there are some concave portion boundaries aligned with the second sidewall 27 of the groove structure, or alternatively, there are some concave portion boundaries in the second concave-convex alternating structure extending above the groove structure; of course, it can also be that the boundaries of all the concave portions in the second concave-convex alternating structure are the second sub-boundaries 34.

[0153] Such as Figure 19As shown, for the convex portions in the second concave-convex alternating structure, at least some of the convex portions may extend above the groove structure along the width direction of the spacer region; alternatively, some of the boundaries of the convex portions in the second concave-convex alternating structure may be aligned with the second sidewall 27 of the groove structure, or alternatively, some of the boundaries of the convex portions in the second concave-convex alternating structure may be located within the second region (i.e., some of the boundaries of the convex portions are the second sub-boundaries 34); of course, it is also possible that all the boundaries of the convex portions in the second concave-convex alternating structure extend above the groove structure along the width direction of the spacer region.

[0154] The application principle of the beneficial effects when at least a part of the second doped semiconductor layer corresponding to at least some of the convex portions is suspended above the groove structure can refer to the application principle of the beneficial effects when at least a part of the first doped semiconductor layer corresponding to at least some of the convex portions is suspended above the groove structure as described above, and will not be elaborated here.

[0155] Regarding the extension width of at least one convex portion in the first concave-convex alternating structure above the groove structure relative to the first sidewall, and / or the extension width of at least one convex portion in the second concave-convex alternating structure above the groove structure relative to the second sidewall, it can be determined according to the requirements for the bifaciality and leakage risk of the back contact battery in the actual application scenario, and no specific limitation is made here.

[0156] Exemplarily, the extension width of at least one convex portion in the first concave-convex alternating structure above the groove structure relative to the first sidewall may be less than or equal to 1 μm. For example: the extension width of at least one convex portion in the first concave-convex alternating structure above the groove structure relative to the first sidewall may be 5 nm, 10 nm, 100 nm, 200 nm, 300 nm, 500 nm, 800 nm or 1 μm, etc., so as to further improve the bifaciality of the back contact battery while making the back contact battery have a lower leakage risk.

[0157] Exemplarily, the extension width of at least one convex portion in the second concave-convex alternating structure above the groove structure relative to the second sidewall may be less than or equal to 1 μm. For example: the extension width of at least one convex portion in the first concave-convex alternating structure above the groove structure relative to the first sidewall may be 5 nm, 10 nm, 100 nm, 200 nm, 300 nm, 500 nm, 800 nm or 1 μm, etc., so as to further improve the bifaciality of the back contact battery while making the back contact battery have a lower leakage risk.

[0158] Exemplarily, as Figure 17 and Figure 18 shown, the portion in the first region 15 close to the first sidewall 26 and not directly covered by the first doped semiconductor layer 12 is the platform region 30, and / or, as Figure 19As shown, the portion in the second region 16 that is close to the second sidewall 27 and not directly covered by the second doped semiconductor layer 13 is the platform region 30. It should be noted that the platform region 30 has a broad meaning, specifically referring to a region, that is, the region in the first region 15 that is close to the first sidewall 26 and not directly covered by the first doped semiconductor layer 12, and / or the region in the second region 16 that is close to the second sidewall 27 and not directly covered by the second doped semiconductor layer 13.

[0159] As Figures 17 to 19 shown, the platform region 30 may include a plane 31 that is substantially parallel to the first surface. At this time, the surface of the portion in the first region 15 of the semiconductor substrate 11 that is not directly covered by the first doped semiconductor layer 12 and / or the portion in the second region 16 that is not directly covered by the second doped semiconductor layer 13 (i.e., the platform region 30) is relatively flat. On the one hand, as a transition region between the first region 15 or the second region 16 and the spacer region 24, it can effectively reduce the leakage risk. And by providing the island-shaped passivation structure 14 at least in part of the platform region 30, the surface of the platform region 30 provided with the island-shaped passivation structure 14 can be passivated, reducing the number of defects on the region surface and reducing the carrier recombination rate. On the other hand, the plane 31 of the platform region 30 increases the light absorption area, promotes the diversification of the light absorption surface morphology, and by providing the island-shaped passivation structure 14 at least in part of the platform region 30, and the island-shaped passivation structure 14 enhances the light absorption, comprehensively improving the light utilization rate of the back contact battery. It should be noted that when the included angle between the plane 31 included in the platform region 30 and the rest of the first surface is less than or equal to 5°, the plane 31 can be considered to be substantially parallel to the first surface.

[0160] Alternatively, the platform region includes a plane having an included angle (greater than 5° and less than the inclination angle of the first sidewall and / or the second sidewall relative to the bottom surface of the groove) with the first surface. In addition, the surface included in the platform region can be a relatively flat plane, or an uneven surface with a pyramidal or hole-shaped structure, etc. The morphology of the surface included in the platform region can be set according to actual needs and will not be specifically limited here.

[0161] In terms of the distribution position, when the first boundary has a first concave-convex alternating structure and the first region has a platform region, the platform region can be provided between at least some of the concave portions in the first concave-convex alternating structure and the first sidewall. Or, as Figure 17 and Figure 18 shown, the platform region 30 can be provided below at least some of the convex portions in the first concave-convex alternating structure. Or, there is a platform region 30 between the concave portion in the first concave-convex alternating structure and the first sidewall 26, and there is also a platform region 30 below at least some of the convex portions in the first concave-convex alternating structure. The specific distribution of the platform region 30 can be set according to actual needs and will not be specifically limited here.

[0162] As for the case where the second boundary has a second concave-convex alternating structure and the second region has a platform region, the distribution of the platform region in the second region may refer to the distribution of the platform region in the case where the first boundary has a first concave-convex alternating structure and the first region has a platform region as described above, which will not be elaborated here.

[0163] As Figure 17 and Figure 19 shown, at least one island-shaped passivation structure 14 included in the back-contact battery may be at least partially disposed on the plane 31 included in the platform region 30. In this case, the size of the plane 31 included in the platform region 30 will affect the size of the island-shaped passivation structure 14. Therefore, the size and morphology of the plane 31 included in the platform region 30 can be determined according to the size requirements of the island-shaped passivation structure 14 in the actual application scenario, and no specific limitation is made here.

[0164] Exemplarily, along the width direction of the spacer region, the width of the plane included in at least one platform region is less than or equal to 1 μm. For example: the width of the plane included in at least one platform region may be 10 nm, 50 nm, 100 nm, 300 nm, 500 nm, 800 nm, 1 μm, etc. In this case, taking the part in the first region that is close to the first sidewall and not directly covered by the first doped semiconductor layer as the platform region as an example: it can be understood that the larger the width of the plane included in the platform region, the larger the distance between the part of the first doped semiconductor layer corresponding to the platform region and the spacer region, and the smaller the area ratio of the first doped semiconductor layer on the first region. Therefore, when the width of the plane included in at least one platform region is within the above range, it is beneficial to improve the bifaciality and passivation effect of the back-contact battery through the island-shaped passivation structure, while enabling the first doped semiconductor layer to have a larger area ratio on the first region, thereby facilitating the first doped semiconductor layer to have a higher field passivation effect and carrier collection ability, and further facilitating the back-contact battery to have a higher conversion efficiency.

[0165] In terms of surface height, as Figure 21 shown, the plane 31 included in the platform region 30 may be flush with the first surface.

[0166] Or, as Figures 22 to 24 and Figures 26 to 28 shown, in the case where the first region 15 has a platform region 30, at least one platform region 30 further includes a third sidewall 32 that is away from the first sidewall 26 and continuous with the plane 31; and / or, in the case where the second region 16 has a platform region 30, at least one platform region 30 further includes a third sidewall 32 that is away from the second sidewall 27 and continuous with the plane 31. Among them, the third sidewall 32 is perpendicular to the plane 31 or the third sidewall 32 is inclined with respect to the plane 31.

[0167] Taking the example that the first region has a platform area, and the platform area also includes a third side wall: the platform area also includes a third side wall continuous with the plane, indicating that along the direction from the first surface to the second surface, the plane is recessed into the semiconductor substrate relative to the surface of the area directly covered by the first doped semiconductor layer in the first region, which can reduce the height variation between the bottom surface of the groove structure and the surface of the area with a larger height in the first region, which is beneficial to the formation quality and coating of the surface passivation layer at the junction of the first region and the spacing region, reduces the carrier recombination rate at the junction of the first region and the spacing region, improves the diversification of the light absorption surface morphology, and improves the light utilization rate of the back contact battery.

[0168] In the case where the platform area also includes a third side wall, such as Figure 18 and Figure 19 As shown, at least one island-shaped passivation structure 14 may be disposed only on the plane 31 of the platform region 30. Alternatively, as shown in FIG. Figure 17 As shown, at least one island-shaped passivation structure 14 can also extend from the plane 31 to at least a portion of the third side wall 32. In this case, it is beneficial to increase the passivation contact area of ​​the island-shaped passivation structure 14 on the side of the first surface, and improve the passivation effect of the island-shaped passivation structure 14. In addition, the surface area of ​​the island-shaped passivation structure 14 on the side away from the semiconductor substrate 11 can also be increased, which is beneficial to enhance the light trapping effect of the first surface provided with the island-shaped passivation structure 14. The extension range of the island-shaped passivation structure 14 on the third side wall 32 can be set according to actual needs, and is not specifically limited here.

[0169] In the case where the terrace region further includes a third sidewall, a portion of the sidewall of the first doped semiconductor layer and / or the second doped semiconductor layer may be aligned with the third sidewall of at least one adjacent terrace region. Figure 19 , Figures 22 to 24 ,as well as Figures 26 to 28As shown, part of the first boundary 28 and / or the second boundary 29 can extend above the plane 31. In this case, when the sidewalls of the first doped semiconductor layer 12 and / or the second doped semiconductor layer 13 are aligned with the third sidewall 32 of at least one adjacent platform region 30, it is beneficial to increase the relatively large spacing between the first doped semiconductor layer 12 and the second doped semiconductor layer 13, which is beneficial to further reduce the leakage risk between the two. When part of the first boundary 28 and / or the second boundary 29 can extend above the plane 31, taking the example where the first region 15 has a platform region 30 and part of the first boundary 28 also extends above the plane 31 included in the platform region 30: Although the spacing between this part of the first boundary 28 and the second doped semiconductor layer 13 is relatively small, the part of the first doped semiconductor layer 12 corresponding to this part of the first boundary 28 can reflect part of the light emitted from the plane 31 and / or reflected by the outer surface of the island-shaped passivation structure 14, so that part of the light can re-enter the semiconductor substrate 11, further improving the light utilization rate of the back-contact battery.

[0170] In addition, as Figure 18 and Figure 19 shown, the first doped semiconductor layer 12 and the island-shaped passivation structure 14 can be spaced apart, which is beneficial to the transmission of light between the outer surface of the island-shaped passivation structure 14 and the inner surface of the part of the first doped semiconductor layer 12 extending above the plane 31. It is beneficial to change the transmission path of the incident light under the action of these two parts, and it is beneficial for more incident light to be refracted into the battery, increasing the absorption ratio of the incident light and further improving the bifaciality of the back-contact battery. Furthermore, when the island-shaped passivation structure 14 includes a doped semiconductor passivation part with a conductivity type opposite to that of the first doped semiconductor layer 12, the spaced-apart distribution of the first doped semiconductor layer 12 and the island-shaped passivation structure 14 is also beneficial to reducing the leakage risk between the two, which is beneficial for the back-contact battery to have a high conversion efficiency. Secondly, when the second boundary 29 extends above the plane 31, the second doped semiconductor layer 13 and the island-shaped passivation structure 14 can also be spaced apart. The beneficial effects in this case can refer to the above, and will not be elaborated here.

[0171] Of course, when an island-shaped passivation structure is provided on the first region, the sidewalls of the first doped semiconductor layer and the sidewalls of the island-shaped passivation structure can also be adjacent; and / or, when an island-shaped passivation structure is provided on the second region, the sidewalls of the second doped semiconductor layer and the sidewalls of the island-shaped passivation structure can also be adjacent.

[0172] Regarding the height of the third sidewall above, in the case where part of the first boundary and / or the second boundary also extends above the plane included in the platform region, the spacing between the corresponding doped semiconductor layer and the island-shaped passivation structure, as well as the extension width of the first boundary and / or the second boundary above the plane, can be determined according to the requirements for the bifaciality and leakage risk of the back-contact battery in the actual application scenario, and no specific limitation is made here.

[0173] Exemplarily, along the thickness direction of the semiconductor substrate, the height of the third sidewall is greater than or equal to 0.05 μm and less than or equal to 8 μm. For example: the height of the third sidewall can be 0.05 μm, 0.1 μm, 1 μm, 2 μm, 3 μm, 5 μm, 6 μm, 7 μm, 8 μm, etc. When the height of the third sidewall is within the above range, it is beneficial to prevent a large height change amplitude between the bottom surface of the groove structure and the surface of the region with a larger height in the first region (and / or the second region) due to the small height of the third sidewall, which is beneficial to further improving the passivation effect at the junction of the first region and the spacer region, and / or, at the junction of the second region and the spacer region. In addition, it can also prevent a large etching amount of the part of the semiconductor substrate corresponding to the platform region due to the large height of the second sidewall, which is beneficial to making the part of the semiconductor substrate corresponding to the platform region have a large light absorption depth, improving the light utilization rate of the semiconductor substrate, and further improving the conversion efficiency of the back-contact battery.

[0174] Exemplarily, in the case where part of the first boundary also extends above the plane included in the platform region, along the thickness direction of the semiconductor substrate, the spacing between the first doped semiconductor layer and the island-shaped passivation structure is greater than or equal to 1 nm and less than or equal to 500 nm. And / or, in the case where part of the second boundary also extends above the plane included in the platform region, along the thickness direction of the semiconductor substrate, the spacing between the second doped semiconductor layer and the island-shaped passivation structure is greater than or equal to 1 nm and less than or equal to 500 nm. Taking the spacing between the first doped semiconductor layer and the island-shaped passivation structure within the above range as an example: it is beneficial for light to be effectively transmitted between the outer surface of the island-shaped passivation structure and the inner surface of the part where the first doped semiconductor layer extends above the plane, so that these two parts can effectively cooperate in changing the transmission path of the incident light, further increasing the absorption ratio of the incident light. In addition, due to the same other factors, when the spacing between the first doped semiconductor layer and the island-shaped passivation structure becomes larger, the etching amount of the part of the semiconductor substrate corresponding to the platform region is larger. Therefore, the spacing between the first doped semiconductor layer and the island-shaped passivation structure within the above range can also make the part of the semiconductor substrate corresponding to the platform region have a large absorption depth and improve the utilization rate of the semiconductor substrate for light.

[0175] Exemplarily, when part of the first boundary also extends above the plane included in the platform area, along the width direction of the spacing area, the extension width of the first boundary relative to the third sidewall is less than or equal to 1 μm. And / or, when part of the second boundary also extends above the plane included in the platform area, along the width direction of the spacing area, the extension width of the second boundary relative to the third sidewall is less than or equal to 1 μm. Taking the case where part of the first boundary also extends above the plane included in the platform area and the extension width is within the above range as an example, it can be prevented that the extended part of the first doped semiconductor layer has a weak reflection effect on light due to the extension width being too small, which is conducive to further improving the bifaciality of the back contact battery.

[0176] Exemplarily, in the case where part of the first boundary also extends above the plane included in the platform area, the extension width of the first boundary relative to the third side wall along the width direction of the spacing area may be greater than or equal to 10nm. And / or, in the case where part of the second boundary also extends above the plane included in the platform area, the extension width of the second boundary relative to the third side wall along the width direction of the spacing area may be greater than or equal to 10nm. Taking the case where part of the first boundary also extends above the plane included in the platform area and the extension width is within the above range as an example, it can prevent the process difficulty of manufacturing the back contact battery due to the excessive extension width, and the leakage risk between the extended part of the first doped semiconductor layer and the second doped semiconductor layer is reduced to a small extent, which is conducive to further improving the conversion efficiency and yield of the contact battery.

[0177] For example: when part of the first boundary also extends above the plane included in the platform area, along the width direction of the spacing area, the extension width of the first boundary relative to the third side wall can be 10nm, 20nm, 50nm, 100nm, 200nm, 500nm, 800nm ​​or 1μm, etc.

[0178] For example: when part of the second boundary also extends above the plane included in the platform area, along the width direction of the spacing area, the extension width of the second boundary relative to the third side wall can be 10nm, 20nm, 50nm, 100nm, 200nm, 500nm, 800nm ​​or 1μm, etc.

[0179] The morphology, size, area, structure, material and other information of the island-shaped passivation structure arranged between the first boundary and the first sidewall, and / or arranged between the second boundary and the first sidewall can refer to the morphology, size, area, structure, material and other information of the island-shaped passivation structure arranged on the side of the first doped semiconductor layer and / or the second doped semiconductor layer away from the semiconductor substrate, and / or arranged between the first doped semiconductor layer and / or the second doped semiconductor layer and the semiconductor substrate as described above, and will not be repeated here.

[0180] Second aspect, embodiments of the present application provide a photovoltaic module. The photovoltaic module includes a battery string and a packaging layer. The battery string is formed by electrically connecting a plurality of back contact batteries provided by the first aspect and its various implementation manners. The packaging layer covers the surface of the battery string.

[0181] For the beneficial effects of the second 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, which will not be elaborated here.

[0182] Unless there are technical obstacles or contradictions, the various technical features disclosed in the present application can be freely combined to form additional embodiments, and these additional embodiments are all within the protection scope of the present application.

[0183] In the above description, no detailed description is made on the technical details such as the composition and etching of each layer. 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 advantageously in combination.

[0184] The above describes the embodiments of the present application. However, these embodiments are only for clearer illustration and not for 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: include: A semiconductor substrate having a first surface and a second surface opposite to each other; The first surface includes first areas and second areas that are alternately distributed; A first doped semiconductor layer, disposed on the first region; A second doped semiconductor layer is disposed on the second region; the second doped semiconductor layer and the first doped semiconductor layer have opposite conductivity types; The island passivation structure is arranged on a side of the first doped semiconductor layer and / or the second doped semiconductor layer away from the semiconductor substrate, and / or is arranged between the first doped semiconductor layer and / or the second doped semiconductor layer and the semiconductor substrate.

2. The back contact cell according to claim 1, characterized in that: At least one of the island-shaped passivation structures includes a plurality of point-shaped passivation portions which are not adjacent to each other and are distributed in a clustered manner; And / or, different regions of at least one of the island-shaped passivation structures are continuously distributed, and a surface of the island-shaped passivation structure has an undulating morphology.

3. The back contact cell according to claim 1, characterized in that: The edge of the island-shaped passivation structure is irregular in shape; And / or, at least part of the island-shaped passivation structures are regularly distributed.

4. The back contact cell according to claim 1, characterized in that: The distance between two adjacent island-shaped passivation structures is greater than or equal to 40 μm and less than or equal to 300 μm.

5. The back contact cell according to claim 1, characterized in that: The first doped semiconductor layer and the second doped semiconductor layer both include strip-shaped doped regions; the strip-shaped doped regions included in the first doped semiconductor layer and the strip-shaped doped regions included in the second doped semiconductor layer both extend along a first direction and are alternately spaced along a second direction; the first direction is different from the second direction; a spacing between two adjacent island-shaped passivation structures along the first direction is smaller than a spacing between two adjacent island-shaped passivation structures along the second direction.

6. The back contact cell according to claim 1, characterized in that: At least one of the island-shaped passivation structures comprises a doped semiconductor passivation portion; and / or, at least one of the island-shaped passivation structures comprises an interface passivation portion; And / or, at least one of the island-shaped passivation structures includes a doped semiconductor passivation portion and a doped silicon glass portion disposed on a side of the doped semiconductor passivation portion facing away from the semiconductor substrate.

7. The back contact cell according to claim 6, characterized in that: At least one of the island-shaped passivation structures disposed on a side of the first doped semiconductor layer facing away from the semiconductor substrate, or, in at least one of the island-shaped passivation structures disposed between the first doped semiconductor layer and the semiconductor substrate, the material and conductivity type of the doped semiconductor passivation portion are respectively the same as the material and conductivity type of the second doped semiconductor layer; And / or, in at least one of the island-shaped passivation structures arranged on the side of the second doped semiconductor layer facing away from the semiconductor substrate, or in at least one of the island-shaped passivation structures arranged between the second doped semiconductor layer and the semiconductor substrate, the material and conductivity type of the doped semiconductor passivation portion are respectively the same as the material and conductivity type of the first doped semiconductor layer.

8. The back contact cell according to claim 6, characterized in that: The back contact cell further comprises a first interface passivation layer disposed between the semiconductor substrate and the first doped semiconductor layer, and a second interface passivation layer disposed between the semiconductor substrate and the second doped semiconductor layer; Wherein, in at least one of the island-shaped passivation structures disposed on the side of the first doped semiconductor layer away from the semiconductor substrate, or in at least one of the island-shaped passivation structures disposed between the first doped semiconductor layer and the semiconductor substrate, the material of the interface passivation portion is the same as the material of the second interface passivation layer; And / or, in at least one of the island-shaped passivation structures arranged on the side of the second doped semiconductor layer facing away from the semiconductor substrate, or in at least one of the island-shaped passivation structures arranged between the second doped semiconductor layer and the semiconductor substrate, the material of the interface passivation portion is the same as the material of the first interface passivation layer.

9. The back contact battery according to claim 6, characterized in that: The back contact cell further comprises a first doped silicon glass layer disposed on a side of the first doped semiconductor layer away from the semiconductor substrate, and a second doped silicon glass layer disposed on a side of the second doped semiconductor layer away from the semiconductor substrate; The first doped silicon glass layer has the same conductivity type as the first doped semiconductor layer; the second doped silicon glass layer has the same conductivity type as the second doped semiconductor layer; Wherein, in at least one of the island-shaped passivation structures disposed on a side of the first doped semiconductor layer away from the semiconductor substrate, or in at least one of the island-shaped passivation structures disposed between the first doped semiconductor layer and the semiconductor substrate, the material and conductivity type of the doped silicon glass portion are respectively the same as the material and conductivity type of the second doped silicon glass layer; And / or, in at least one of the island-shaped passivation structures arranged on the side of the second doped semiconductor layer facing away from the semiconductor substrate, or in at least one of the island-shaped passivation structures arranged between the second doped semiconductor layer and the semiconductor substrate, the material and conductivity type of the doped silicon glass part are respectively the same as the material and conductivity type of the first doped silicon glass layer.

10. The back contact battery according to any one of claims 1 to 9, characterized in that: The island-shaped passivation structure disposed on the first region is located on a side of the first doped semiconductor layer away from the semiconductor substrate, and the island-shaped passivation structure disposed on the second region is disposed between the second doped semiconductor layer and the semiconductor substrate; Alternatively, the island-shaped passivation structure disposed on the first region is located between the first doped semiconductor layer and the semiconductor substrate, and the island-shaped passivation structure disposed on the second region is disposed on a side of the second doped semiconductor layer away from the semiconductor substrate.

11. The back contact battery according to any one of claims 1 to 9, characterized in that: The area occupied by at least one of the island-shaped passivation structures is greater than or equal to 1 μm 2 , and less than or equal to 100μm 2 .

12. The back contact cell according to any one of claims 1 to 9, characterized in that: The first surface further includes a spacing region between the first region and the second region; along the direction from the first surface to the second surface, the surface of the spacing region is recessed into the semiconductor substrate relative to the surface of the first region to form a groove structure; the groove structure has a first sidewall close to the first region, and a second sidewall close to the second region; The first doped semiconductor layer has a first boundary close to the spacing region; the second doped semiconductor layer has a second boundary close to the spacing region; At least one of the island-shaped passivation structures is at least partially located between the first boundary and the first sidewall; And / or, at least one of the island-shaped passivation structures is at least partially located between the second boundary and the second sidewall.

13. A photovoltaic module, characterized in that: The photovoltaic module comprises: 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 12; and a packaging layer covering the surface of the battery string.

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