Solar cell, cell arrangement and photovoltaic system

Abstract

Solar cell, comprehensive: a silicon wafer, having a first surface and a second surface opposite each other; P-type doped layers and N-type doped layers arranged on the first surface of the silicon wafer; and a passivation film layer arranged on the P-type doped layers and the N-type doped layers, wherein the passivation film layer has a first thickness on at least some areas of the N-type doped layers, wherein the passivation film layer has a second thickness on at least some areas of the P-type doped layers, and wherein the first thickness is greater than the second thickness.

Description

Reference to the associated registration

[0001] The present disclosure claims priority from Chinese patent application 202411000880.2, filed with the China National Intellectual Property Administration on July 24, 2024, entitled “Solar cell, cell arrangement and photovoltaic system”, the entire contents of which are incorporated herein by reference. Technical field

[0002] The present disclosure relates to the technical field of solar cells and specifically to a solar cell, a cell arrangement and a photovoltaic system. background

[0003] Electricity generation through solar cells is a sustainable and clean energy source that utilizes the photovoltaic effect of pn junctions in semiconductors to convert sunlight into electrical energy. In a solar cell, a p-type doped layer and an n-type doped layer are arranged on a silicon wafer, and passivation film layers are applied to the doped layers to passivate the cell.

[0004] In current solar cells, the mutually cooperating optimization between the passivation film layer on the P-type doped layer and the N-type doped layer has not been fully considered to improve the passivation effect, resulting in poor performance of current solar cells. Summary

[0005] The present disclosure relates to a solar cell, a cell arrangement and a photovoltaic system.

[0006] The present disclosure is implemented such that the solar cell in the embodiments of the present disclosure comprises the following: a silicon wafer, having a first surface and a second surface opposite each other; P-type doped layers and N-type doped layers arranged on the first surface of the silicon wafer; and a passivation film layer arranged on the P-type doped layers and the N-type doped layers, wherein the passivation film layer has a first thickness on at least some areas of the N-type doped layers, the passivation film layer has a second thickness on at least some areas of the P-type doped layers, and the first thickness is greater than the second thickness.

[0007] In some embodiments, the first surface has a boundary region and an intermediate region, wherein the intermediate region is located on an inside of the boundary region and the boundary region is closer to an edge of the first surface than the intermediate region; and a section of at least one N-type doped layer located on the intermediate region is a first N-type doped section, the passivation film layer located on the first N-type doped section has the first thickness, a section of at least one P-type doped layer located on the intermediate region is a first P-type doped section, and the passivation film layer located on the first P-type doped section has the second thickness.

[0008] In some embodiments, a section of at least one N-type doped layer located on the edge region is a second N-type doped section, the passivation film layer located on the second N-type doped section has a third thickness, a section of at least one P-type doped layer located on the edge region is a second P-type doped section, the passivation film layer located on the second P-type doped section has a fourth thickness, the third thickness is greater than the first thickness and the fourth thickness is greater than the second thickness.

[0009] In some embodiments, the third thickness is greater than the fourth thickness.

[0010] In some embodiments, the passivation film layer covering the intermediate area has an integrated continuous structure.

[0011] In some embodiments, the ratio of the first thickness to the second thickness is greater than 1 and less than or equal to 2.

[0012] In some embodiments, the ratio of the first thickness to the second thickness is 1.025 to 1.6.

[0013] In some embodiments, the difference between the first thickness and the second thickness is between 2 nm and 50 nm.

[0014] In some embodiments, the difference between the first thickness and the second thickness is 5 nm to 30 nm.

[0015] In some embodiments, the first thickness is 52 nm to 250 nm and the second thickness is 50 nm to 200 nm.

[0016] In some embodiments, the first thickness is 55 nm to 230 nm and the second thickness is 50 nm to 200 nm.

[0017] In some embodiments, a spacer area is located on the intermediate region between a P-type doped layer and an N-type doped layer that are adjacent to each other; the passivation film layer further covers the spacer area; a section of the passivation film layer located on the spacer area has a fifth thickness, and the second thickness is greater than the fifth thickness.

[0018] In some embodiments, the passivation film layer on the P-type doped layers, the passivation film layer on the N-type doped layers, and the passivation film layer on the spacer regions form an integrated continuous structure in the intermediate area.

[0019] In some embodiments, the ratio of the second thickness to the third thickness is greater than 1 and less than or equal to 2.

[0020] In some embodiments, the ratio of the second thickness to the third thickness is 1.1 to 1.8.

[0021] In some embodiments, the difference between the second thickness and the third thickness is between 2 nm and 50 nm.

[0022] In some embodiments, the difference between the second thickness and the third thickness is 20 nm to 40 nm.

[0023] In some embodiments, the second thickness is 50 nm to 200 nm and the third thickness is 48 nm to 150 nm.

[0024] In some embodiments, the second thickness is 50 nm to 200 nm and the third thickness is 30 nm to 160 nm.

[0025] In some embodiments, the specific resistance of the silicon wafer is greater than 20 Ohm·cm and the difference between the second thickness and the fifth thickness is 10 nm to 60 nm.

[0026] In some embodiments, the spacer area is a groove formed on the first surface, the passivation film layer covers a side surface and a bottom surface of the groove, and the thickness of at least some areas of the passivation film layer located on the side surface of the groove is greater than the thickness of the passivation film layer located on the bottom surface of the groove.

[0027] In some embodiments, the solar cell also fulfills at least one of the following conditions: The N-type doped layer is provided with a first extension section that extends to a top surface of the groove and floats above the groove, and an end section of the first extension section and a surface of the first extension section facing the groove are both provided with the passivation film layer, wherein the thickness of the passivation film layer located on the surface of the first extension section facing the groove is greater than the thickness of the passivation film layer located on the bottom surface of the groove; and the P-type doped layer is provided with a second extension section that extends to the top of the groove and floats above the groove, and an end section of the second extension section and a surface of the second extension section facing the groove are both provided with the passivation film layer, wherein a thickness of the passivation film layer located on the surface of the second extension section facing the groove is greater than the thickness of the passivation film layer located on the bottom surface of the groove.

[0028] In some embodiments, the spacer area is a projection located between the P-type doped layer and the N-type doped layer adjacent to each other, one top surface of the projection is higher than one top surface of the P-type doped layer and one top surface of the N-type doped layer, the top surface and one side surface of the projection are both provided with the passivation film layer, and the thickness of the passivation film layer located on the top surface of the projection is greater than the thickness of the passivation film layer located on the side surface of the projection.

[0029] In some embodiments, a section of the passivation film layer located in the intermediate region comprises at least one passivation sublayer of a first type and at least one passivation sublayer of a second type arranged one above the other, and a thickness of the passivation film layer located in the intermediate region is the sum of a thickness of the passivation sublayer of the first type and the thickness of the passivation sublayer of the second type; and The thickness of a section of the first-type passivation sublayer located on the N-type doped layer is greater than the thickness of a section of the first-type passivation sublayer located on the P-type doped layer.

[0030] In some embodiments, the thickness of a section of the second-type passivation sublayer located on the N-type doped layer is equal to the thickness of a section of the second-type passivation sublayer located on the P-type doped layer.

[0031] In some embodiments, the passivation sublayer of the first type is produced by a Plasma Enhanced Chemical Vapor Deposition (PECVD) process or a thermal growth process, and the passivation sublayer of the second type is produced by an atomic deposition process.

[0032] In some embodiments, the passivation sublayer of the first type comprises at least one silicon oxide film layer and one silicon nitride film layer, and the passivation sublayer of the second type comprises an aluminum oxide film layer.

[0033] In some embodiments, the silicon oxide layer consists of a plurality of layers of silicon oxide arranged one on top of the other in succession, the silicon nitride layer consists of a plurality of layers of silicon nitride arranged one on top of the other in succession, and a silicon oxynitride layer consists of a plurality of layers of silicon oxynitride arranged one on top of the other in succession.

[0034] The present disclosure further provides for a cell arrangement comprising several of the above-mentioned solar cells.

[0035] The present disclosure further provides for a photovoltaic system comprising the above-mentioned cell arrangement.

[0036] In the solar cell, cell arrangement and photovoltaic system in the embodiments of the present disclosure, the P-type doped layers and the N-type doped layers are arranged on the first surface of the silicon wafer and the thickness of the passivation film layer on at least some areas of the N-type doped layers is greater than the thickness of at least some areas of the passivation film layer on the P-type doped layers.In this way, by carrying out a cooperating optimization design of different thicknesses of the passivation film layer on at least some areas of the N-type doped layers and at least some areas of the P-type doped layers, and by adjusting the thickness of the passivation film layer on at least some areas of the N-type doped layers to a larger value, the passivation effects of different doped areas of the solar cell can achieve a better matching effect, thereby improving the performance of the solar cell while simultaneously reducing material consumption and costs.

[0037] Further aspects and benefits of the present revelation are partly specified in the following description, partly become apparent from the following description, or can be learned from the practice of the present revelation. Brief description of the drawings Fig. Figure 1 is a schematic diagram of modules of a photovoltaic system according to an embodiment of the present disclosure; Fig. Figure 2 is a schematic diagram of a cross-sectional structure of a solar cell according to an embodiment of the present disclosure; Fig. Figure 3 is a schematic diagram of a planar structure of a substructure of a solar cell according to an embodiment of the present disclosure; Fig. Figure 4 is a schematic diagram of a cross-sectional structure of a solar cell according to an embodiment of the present disclosure in an intermediate region; Fig. Figure 5 is a schematic structure diagram of a passivation film layer according to an embodiment of the present disclosure in an intermediate region; Fig. Figure 6 is a schematic diagram of a further cross-sectional structure of a solar cell according to an embodiment of the present disclosure in the intermediate area; Fig. Figure 7 is a schematic diagram of yet another cross-sectional structure of a solar cell according to an embodiment of the present disclosure in the intermediate area; Fig. Figure 8 is a schematic diagram of yet another cross-sectional structure of a solar cell according to an embodiment of the present disclosure in the intermediate region; and Fig. Figure 9 is a schematic diagram of yet another cross-sectional structure of a solar cell according to an embodiment of the present disclosure in the intermediate area. Detailed description of the embodiments

[0038] To clarify the objectives, technical solutions, and advantages of this disclosure, it is further described in detail below in conjunction with the drawings and embodiments. Examples of embodiments are shown in the drawings, where identical or similar reference numerals consistently denote identical or similar elements or elements with identical or similar functions. It should be noted that the embodiments described below with reference to the drawings are exemplary and serve only to illustrate this disclosure; they cannot be construed as limiting it. Furthermore, it should be understood that the specific embodiments described herein serve only to illustrate this disclosure and are not intended to limit it.

[0039] In describing the present disclosure, it should be noted that the orientation or positional relationships designated by the terms "upper", "lower", "left", "right", "top", "bottom", "side surface" and the like are illustrated on the basis of the drawings and serve only to simplify the description of the present disclosure, but do not mean or imply that the devices or elements mentioned must have certain orientations or be designed and operated in certain orientations, and therefore cannot be interpreted as limitations of the present disclosure.

[0040] Furthermore, the terms “first”, “second”, and the like are used for descriptive purposes only and cannot be understood as indicating or implying a relative meaning or implying the number of specified technical features. Therefore, features defined as “first” and “second” may explicitly or implicitly include one or more of the features. In the description of this disclosure, “several” means two or more unless expressly defined otherwise.

[0041] In the present disclosure, unless otherwise specified and limited, a first feature located "on" or "below" a second feature may include the first feature being in direct contact with the second feature, or the first feature not being in contact with the second feature but being connected to the second feature via an additional intervening feature. Furthermore, a first feature located "above," "above," and "on" the second feature may include the first feature being located directly above and obliquely above the second feature, or simply indicate that the horizontal height of the first feature is greater than that of the second feature.The fact that the first feature is located "below", "underneath", and "below" the second feature implies that the first feature is located directly below and diagonally below the second feature, or simply indicates that the horizontal height of the first feature is less than that of the second feature.

[0042] The following disclosure contains many different embodiments or examples for implementing various structures of the present disclosure. To simplify the disclosure of the present disclosure, components and settings of specific examples are described below. Of course, these are merely examples and are not intended to limit the present disclosure. Furthermore, reference numbers and / or reference letters may be repeated in various examples in the present disclosure, with such repetition serving for simplicity and clarity and not indicating the relationship between the various embodiments and / or settings discussed. In addition, the present disclosure gives examples of various specific processes and materials, but those skilled in the art may be aware of applications of other processes and / or use scenarios for other materials.

[0043] With reference to Fig. 1. A photovoltaic system 1000 in the embodiments of the present disclosure may comprise a cell arrangement 200 in the embodiments of the present disclosure, the cell arrangement 200 in the embodiments of the present disclosure may comprise several solar cells 100 in the embodiments of the present disclosure, the several solar cells 100 may be connected in series by means of a solder strip to form several battery strings, and the battery strings may form the cell arrangement 200 in a series, parallel or series-parallel arrangement.

[0044] With reference to Fig. 2. In the embodiments of the present disclosure, the solar cell 100 may comprise a silicon wafer 10, P-type doped layers 20, N-type doped layers 30 and a passivation film layer 40.

[0045] The silicon wafer 10 has a first surface 11 and a second surface 12, which are opposite each other, and the P-type doped layers 20 and the N-type doped layers 30 are arranged on the first surface 11 of the silicon wafer 10. The passivation film layer 40 covers the first surface 11 and the P-type doped layers 20 and the N-type doped layers 30 are covered by the passivation film layer 40.

[0046] As in Fig. As shown in Figure 2, the passivation film layer 40 has a first thickness D1 on at least some areas of the N-type doped layers 30, the passivation film layer 40 has a second thickness D2 on at least some areas of the P-type doped layers 20, and the first thickness D1 is greater than the second thickness D2.

[0047] In the solar cell 100, the cell arrangement 200 and the photovoltaic system 1000 in the embodiments of the present disclosure, the P-type doped layers 20 and the N-type doped layers 30 are arranged on the first surface 11 of the silicon wafer 10 and the thickness of the passivation film layer 40 on at least some areas of the N-type doped layers 30 is greater than the thickness of the passivation film layer 40 on at least some areas of the P-type doped layers 20, i.e. the first thickness D1 is greater than the second thickness D2.In this way, by carrying out a cooperating optimization design of different thicknesses of the passivation film layer 40 on at least some areas of the N-type doped layers 30 and at least some areas of the P-type doped layers 20, and by adjusting the thickness of the passivation film layer 40 on at least some areas of the N-type doped layers 30 to a larger value, the passivation effects of different doped areas of the solar cell 100 can achieve a better matching effect, thereby improving the performance of the solar cell 100 while simultaneously reducing material consumption and costs.

[0048] In particular, in the embodiments of the present disclosure, the first surface 11 can be a back side of the silicon wafer 10 and the second surface 12 can be a front side of the silicon wafer 10. The solar cell 100 is preferably a back-contact solar cell. Of course, in some embodiments, the solar cell 100 can also be a different cell type having the P-type doped layers 20 and the N-type doped layers 30 on the same surface, which is not specifically limited herein.

[0049] The silicon wafer 10 can be a P-type silicon wafer or an N-type silicon wafer, which is not specifically limited herein; the P-type doped layer 20 can be a P-type doped polysilicon layer, a P-type doped microcrystalline silicon layer, and the like; the N-type doped layer 30 can be an N-type doped polysilicon layer, an N-type doped microcrystalline silicon layer, and the like; and the P-type doped layer 20 and the N-type doped layer 30 can be produced by diffusion, deposition, and other processes, which is not specifically limited herein.

[0050] It should be noted that in the present disclosure, the thickness of the passivation film layer 40 on the N-type doped layer 30 refers to the thickness of the passivation film layer 40 on all surfaces of the N-type doped layer 30 that are covered with the passivation film layer 40, and similarly, that the thickness of the passivation film layer 40 on the P-type doped layer 20 refers to the thickness of the passivation film layer 40 on all surfaces of the P-type doped layer 20 that are covered with the passivation film layer 40.

[0051] Furthermore, a particular film layer covering a particular surface or film layer may be such that the film layer is arranged directly on the particular surface or film layer, or another film layer may furthermore be arranged between the film layer and the surface or film layer, and the covering is used merely to limit a particular adjustment range of the film layer.

[0052] It is understandable that in the back-contact solar cell, the first surface 11 is provided with several P-type doped layers 20 and several N-type doped layers 30, and that the multiple P-type doped layers 20 and the multiple N-type doped layers 30 are arranged alternately in sequence. Furthermore, it is not difficult to understand that tunnel layers (not shown in the figures) can also be generally arranged between the P-type doped layers 20, the N-type doped layers 30, and the silicon wafer 10 in the back-contact solar cell.

[0053] With reference to Fig. 2 and Fig. 4 In some embodiments, the first surface 11 has a boundary region 111 and an intermediate region 112, the intermediate region 111 being located on an inside of the boundary region 112 and the boundary region 111 being closer to an edge of the first surface 11 than the intermediate region 112.

[0054] The passivation film layer 40 on the section of the N-type doped layer 30 located on the intermediate region 112 has the first thickness D1 and the passivation film layer 40 on the section of the P-type doped layer 20 located on the intermediate region 112 has the second thickness D2.

[0055] In this way, the passivation effects of the areas corresponding to the N-type doped layer 30 and the P-type doped layer 20 in the intermediate area 112 can achieve a better effect, thereby improving the performance of the solar cell 100.

[0056] In particular, as in Fig. As shown in Figure 2, in such an embodiment the silicon wafer 10 further comprises several side surfaces 13 for connecting the first surface 11 and the second surface 12, the edge region 111 is located at a boundary edge position between the first surface 11 and the side surface 13, the intermediate region 112 is located at an intermediate position of the first surface 11 and the edge region 111 is located between the intermediate region 112 and the side surface 13.

[0057] As in Fig. As shown in Figure 2, the “boundary region 111” refers to a region located near an edge of a boundary between the first surface 11 and the side surface 13, and the “intermediate region 112” refers to a region other than the boundary region 111 in the first surface 11.

[0058] As in Fig. 3 shown (the passivation film layer 40 is in Fig. (3 not shown), in some embodiments a specific setting of the intermediate region 112 and the edge region 111 as in Fig. 3 shown, wherein in such an embodiment the edge region 111 can be arranged around the intermediate region, i.e., the boundaries between the edge of the first surface 11 and all side surfaces 13 are provided with the edge region 111, and the intermediate region 112 lies within the edge region 110, i.e., the edge region 11 is a region that is located at each edge position of the first surface 11.

[0059] Of course, in some embodiments there may also be no edge region at an edge of a boundary between a section of the first surface 11 and the side surface 13, for example in one possible embodiment, in a half-cell, after the cutting is completed, a cut surface is formed on the half-cell, and the cut surface is also the side surface 13, in this case there is no edge region 110 at the boundary edge between the first surface 11 and the cut surface, but there is the edge region 110 near other boundary edges.

[0060] With reference to Fig. In some embodiments, the passivation film layer 40 on the section of the N-type doped layer 30 located on the edge region 111 has a third thickness D3, the passivation film layer 40 on the section of the P-type doped layer 20 located on the edge region 111 has a fourth thickness D4, the third thickness D3 is greater than the first thickness D1 and the fourth thickness D4 is greater than the second thickness D2.

[0061] In this way, by adjusting the thickness of the passivation film layer on the doped layer at the edge region 111 to a larger value, the passivation effect of the edge region 111 can be improved, edge recombination reduced and the efficiency of the solar cell 100 further improved.

[0062] Furthermore, in such an embodiment, the third thickness D3 can be greater than the fourth thickness D4. In this way, by carrying out a coordinated optimization of different thicknesses of the passivation film layer 40 on the N-type doped layer 30 and the P-type doped layer 20 in the edge region 111, and by adjusting the thickness of the passivation film layer 40 on the N-type doped layer 30 to a larger value, the passivation effect of the edge region 11 can achieve an optimal adaptation effect.

[0063] In some embodiments, the passivation film layer 40, which covers the intermediate region 112, has an integrated continuous structure.

[0064] In this way, this section of the passivation film layer 40 can be produced directly in one step by a PECVD process, and different thicknesses of different areas can be achieved in the manufacturing process by controlling the conductivity of different areas.

[0065] In particular, the term "integrated continuous structure" here refers to the fact that the passivation film layer 40 has the same material and structure on different sections; that the passivation film layer 40 on the different sections is a single, continuous film layer produced in one process, but exhibiting different thicknesses in different areas. Where the same description appears below, reference may be made to the understanding contained herein.

[0066] It is understood that the solar cell 100 further comprises metal electrodes, and that the metal electrodes penetrate the passivation film layer 40 to make contact with the doped layer, i.e., that in a subsequent manufacturing process, when the metal electrodes are produced, the passivation film layer 40 can be removed or abraded at the position corresponding to the metal electrodes. In particular, the back-contact solar cell has P-type electrodes and N-type electrodes (not shown in the figures), the P-type electrode penetrating the passivation film layer 40 to make contact with the P-type doped layer 20, and the N-type electrode penetrating the passivation film layer 20 to make contact with an N-type doped layer 13.

[0067] Referring to Fig. 5 In some embodiments, the section of the passivation film layer 40 located in the intermediate region 112 comprises at least one passivation sublayer 41 of a first type and at least one passivation sublayer 42 of a second type arranged one above the other, and the thickness of the passivation film layer 40 located in the intermediate region 112 is a sum of the thickness of the passivation sublayer 41 of the first type and the thickness of the passivation sublayer 42 of the second type; and The thickness of the section of the first-type passivation sublayer 41 located on the N-type doped layer 30 is greater than the thickness of the section of the first-type passivation sublayer 41 located on the P-type doped layer 20.

[0068] In this way, on the one hand, since the passivation film layer 40 on the intermediate area 112 uses a structure of passivation sublayers of different types, the passivation effect can be improved; and on the other hand, by setting the thickness of the passivation sublayer 41 of the first type, which is located on the N-type doped layer 30, to a value that is greater than the thickness of the passivation sublayer 41 of the first type, which is located on the P-type doped layer 20, the thickness of the passivation film layer 40 on the intermediate area 112, which is located on the N-type doped layer 30, is greater than the thickness of the passivation film layer 40 on the intermediate area 112, which is located on the P-type doped layer 20.

[0069] Furthermore, in such an embodiment, the thickness of the section of the passivation sublayer 42 of the second type, which is located on the N-type doped layer 30, is equal to the thickness of the section of the passivation sublayer 42 of the second type, which is located on the P-type doped layer 20.

[0070] In some embodiments, the passivation sublayer 41 of the first type is produced by the PECVD process or a thermal growth process, and the passivation sublayer 42 of the second type is produced by an atomic deposition process.

[0071] In particular, in the embodiments of the present disclosure, the passivation sublayer 41 of the first type can comprise at least one silicon oxide film layer, one silicon nitride film layer and one silicon oxynitride film layer, and the passivation sublayer 42 of the second type can comprise an aluminum oxide film layer, as shown in Fig. 4 shown.

[0072] As in Fig. As shown in Figure 5, in some embodiments the passivation film layer 40 on the intermediate region 112 can use a three-layer stacked structure of a silicon oxide film layer 401, an aluminum oxide film layer 402 and a silicon nitride film layer 403, the thicknesses of the aluminum oxide film layer 401 on the P-type doped layer 20 and the N-type doped layer 30 can be substantially the same, the thickness of the silicon oxide film layer 401 on the N-type doped layer 30 can be greater than the thickness of the silicon oxide film layer 401 on the P-type doped layer 20, and the thickness of the silicon nitride layer 403 on the N-type doped layer 30 can be greater than the thickness of the silicon nitride layer 403 on the P-type doped layer 20.

[0073] Of course, in some embodiments, the passivation film layer 40 on the intermediate region 112 can also use only a two-layer stacked structure consisting of the aluminum oxide layer 402 and the silicon nitride film layer 403, the thicknesses of the aluminum oxide layer 401 on the P-type doped layer 20 and the N-type doped layer 30 can be essentially the same, and the thickness of the silicon nitride film layer 403 on the N-type doped layer 30 can be greater than the thickness of the silicon nitride film layer 403 on the P-type doped layer 20.

[0074] Furthermore, it should be noted that in some embodiments the silicon nitride film layer 403 may be a single-layer film structure or a multi-layer film structure consisting of a plurality of silicon nitride layers with different refractive indices, which is not specifically limited herein.

[0075] Furthermore, in some embodiments of the solar cell 100, the silicon oxide film layer can be a plurality of silicon oxide layers arranged in series, the silicon nitride film layer can be a plurality of silicon nitride layers arranged in series, and the silicon oxynitride film layer can be a plurality of silicon oxynitride layers arranged in series. That is, in some possible embodiments, the silicon oxide film layer, the silicon nitride film layer, and the silicon oxynitride film layer can each have a multilayer structure.

[0076] In some embodiments, the ratio of the first thickness D1 to the second thickness D2 is greater than 1 and less than or equal to 2, i.e., 1 <D1 / D2≤2.

[0077] Since the thickness of the passivation film layer 40 on the N-type doped layer 30 in the intermediate area 112 is relatively large, the passivation effect of the area corresponding to the N-type doped layer 30 can be improved in this way, so that the passivation effects of the areas corresponding to the P-type doped layer 20 and the N-type doped layer 30 achieve a better matching effect, thereby improving the performance of the solar cell 100.

[0078] In particular, in such an embodiment the ratio of the first thickness D1 to the second thickness D2 may be, for example, 1.01, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, 2 or any numerical value greater than 1 and less than or equal to 2, which is not specifically limited herein.

[0079] In some embodiments, the ratio of the first thickness D1 to the second thickness D2 can preferably be 1.025 to 1.6. Through repeated investigations and verification by the inventor of the present disclosure, it was found that by adjusting the ratio of the first thickness D1 to the second thickness D2 within this preferred range, the costs are also relatively low in a case where the passivation effects of the areas corresponding to the P-type doped layer 20 and the N-type doped layer 30 can achieve an optimal matching effect.

[0080] In particular, in such an embodiment, a preferred ratio of the first thickness D1 to the second thickness D2 may be, for example, 1.025, 1.03, 1.04, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6 or any numerical value between 1.025 and 1.6.

[0081] In some embodiments, the difference between the first thickness D1 and the second thickness D2 can range from 2 nm to 50 nm. By appropriately designing the difference between the two thicknesses, the passivation effects of the areas corresponding to the P-type doped layer 20 and the N-type doped layer 30 can be better matched, thereby improving the performance of the solar cell 100.

[0082] In such an embodiment, the difference between the first thickness D1 and the second thickness D2 can preferably be between 5 nm and 30 nm. Through repeated investigations and verification by the inventor of the present disclosure, it was found that by adjusting the difference between the first thickness D1 and the second thickness D2 within this preferred range, the costs are also relatively low in a case where the passivation effects of the areas corresponding to the P-type doped layer 20 and the N-type doped layer 30 can achieve an optimal matching effect.

[0083] In particular, in such an embodiment, the difference value between the first thickness D1 and the second thickness D2 can preferably be 5 nm, 7 nm, 9 nm, 10 nm, 12 nm, 14 nm, 16 nm, 18 nm, 20 nm, 22 nm, 24 nm, 26 nm, 28 nm, 30 nm or any numerical value between 5 nm and 30 nm.

[0084] In some embodiments, the first thickness D1 can be from 52 nm to 250 nm and the second thickness D2 can be from 50 nm to 200 nm. In this way, the passivation film layer 40 can achieve a good passivation effect by adjusting the first thickness D1 and the second thickness D2 within the aforementioned ranges, and the costs are also relatively low.

[0085] In such an embodiment, the first thickness D1 can preferably be 55 nm to 230 nm and the second thickness D2 can be 50 nm to 200 nm. Through repeated investigations and verification by the inventor of the present disclosure, it was found that by adjusting the dimensions of the first thickness D1 and the second thickness D2 within this preferred range, the passivation effects of the regions corresponding to the P-type doped layer 20 and the N-type doped layer 30 can achieve an optimal match, while at the same time the costs can also be relatively low.

[0086] In a preferred embodiment, the first thickness D1 is preferably 55 nm to 230 nm, the second thickness D2 is preferably 50 nm to 200 nm, the difference between the first thickness D1 and the second thickness D2 is preferably 5 nm to 30 nm, and the ratio of the first thickness D1 to the second thickness D2 is preferably 1.025 to 1.6. In this way, the passivation effects of the areas corresponding to the P-type doped layer 20 and the N-type doped layer 30 can achieve an optimal matching effect, while at the same time the costs are also relatively low.

[0087] With reference to Fig. 4 In some embodiments, the solar cell 100 is a back-contact solar cell, in which case a gap region 120 is arranged between the P-type doped layer 20 and the N-type doped layer 30, which are adjacent to each other, on the intermediate region 112, the passivation film layer 40 further covers the gap region 120, and the section of the passivation film layer 40 which is located on the gap region 120 has a fifth thickness D5, wherein the first thickness D1 is greater than the second thickness D2 and the second thickness D2 is greater than the fifth thickness D5.

[0088] In this way, by appropriately and optimally designing the thicknesses of the passivation film layer 40 on the N-type doped layer 30, the P-type doped layer 20 and the spacing region 120 between the N-type doped layer 30 and the P-type doped layer 20 on the intermediate region 112, the passivation effects of the areas corresponding to the three elements achieve a good matching effect and the electrical performance of the solar cell 100 is improved under the condition that the costs are relatively low.

[0089] In such an embodiment, the passivation film layer 40 on the P-type doped layer 20, the passivation film layer 40 on the N-type doped layer 30, and the passivation film layer 40 at the distance region 120 have an integrated continuous structure in the intermediate region 112. In this way, the passivation film layer can be produced directly in a single step using the PECVD process, and different thicknesses of the various regions can be achieved by controlling the conductivity of the different regions during the manufacturing process.

[0090] Furthermore, in some embodiments, the ratio of the second thickness D2 to the fifth thickness D5 can be greater than 1 and less than 2, i.e., 1 <D2 / D5≤2.

[0091] In this way, by designing the fifth thickness D5, the second thickness D2 and the first thickness D1 in a gradually increasing manner and according to the above-mentioned ratios, the passivation effect of the entire solar cell 100 achieves a better adaptation effect, thereby improving the performance of the solar cell 100 while also keeping costs relatively low.

[0092] In particular, in such an embodiment, the ratio of the second thickness D2 to the fifth thickness D5 may be, for example, 1.01, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, 2 or any numerical value greater than 1 and less than or equal to 2, which is not specifically limited herein.

[0093] In some embodiments of the back-contact solar cell, the ratio of the second thickness D2 to the fifth thickness D5 can preferably be 1.1 to 1.8. Through repeated investigations and verification by the inventor of the present disclosure, it was found that by adjusting the ratio of the second thickness D2 to the fifth thickness D5 within this preferred range, the passivation effects of the areas corresponding to the P-type doped layer 20, the N-type doped layer 30, and the spacing region 120 can achieve an optimal adaptation effect, while at the same time the costs are also relatively low.

[0094] In particular, in such an embodiment, a preferred ratio of the second thickness D2 to the fifth thickness D5 may be, for example, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8 or any numerical value between 1.1 and 1.8.

[0095] In some embodiments, the difference between the second thickness D2 and the fifth thickness D5 can range from 2 nm to 50 nm. By appropriately designing the difference between the two thicknesses, the passivation effects of the solar cell 100 regions can be better matched, thereby improving the performance of the solar cell 100.

[0096] In such an embodiment, the difference between the second thickness D2 and the fifth thickness D5 can preferably be 20 nm to 40 nm. Through repeated investigations and verification by the inventor of the present disclosure, it was found that in the back-contact solar cell, by adjusting the difference between the second thickness D2 and the fifth thickness D5 within this preferred range, the passivation effects of the areas corresponding to the P-type doped layer 20, the N-type doped layer 30, and the spacing range 120 can achieve an optimal matching effect, thereby improving the performance of the solar cell 100 while also keeping costs relatively low.

[0097] In particular, in such an embodiment, the difference value between the second thickness D2 and the fifth thickness D5 can preferably be 20 nm, 22 nm, 24 nm, 26 nm, 28 nm, 30 nm, 32 nm, 34 nm, 36 nm, 38 nm, 40 nm or any numerical value between 20 nm and 40 nm.

[0098] In some embodiments, the second thickness D2 can be 50 nm to 200 nm and the fifth thickness D5 can be 48 nm to 150 nm. In this way, the passivation film layer 40 can achieve a good passivation effect by adjusting the second thickness D2 and the fifth thickness D5 within the aforementioned ranges, and the cost is relatively low.

[0099] In such an embodiment, the second thickness D2 can be 50 nm to 200 nm and the fifth thickness D5 can preferably be 30 nm to 160 nm. In particular, repeated investigations and verification by the inventor of the present disclosure have shown that by adjusting the dimensions of the second thickness D2 and the fifth thickness D5 within this preferred range, the passivation effects of the regions corresponding to the P-type doped layer 20, the N-type doped layer 30 and the spacing range 120 can achieve an optimal match, while at the same time the costs are also relatively low.

[0100] In a preferred embodiment, the first thickness D1 is preferably 55 nm to 230 nm, the second thickness D2 is preferably 50 nm to 200 nm, the fifth thickness D5 is preferably 30 nm to 160 nm, the difference between the first thickness D1 and the second thickness D2 is preferably 5 nm to 30 nm, the difference between the second thickness D2 and the fifth thickness D5 is preferably 20 nm to 40 nm, the ratio of the first thickness D1 to the second thickness D2 is preferably 1.025 to 1.6 and the ratio of the second thickness D2 to the fifth thickness D5 is preferably 1.1 to 1.8. In this way, the passivation effects of the areas corresponding to the P-type doped layer 20, the N-type doped layer 30 and the spacing area 120 in the intermediate area 112 can achieve an optimal matching effect, thereby improving the performance of the solar cell 100 while keeping costs relatively low.

[0101] In some embodiments, the specific resistance of the silicon wafer 10 is greater than 20 Ohm·cm and the difference value between the second thickness D2 and the fifth thickness D5 is 10 nm to 60 nm.

[0102] In this way, if the silicon wafer 10 is a high-resistance silicon wafer 10 with a specific resistance of more than 20 Ohm·cm, by adjusting the difference value between the second thickness D2 and the fifth thickness D5 within this range, the passivation effect of the area corresponding to the P-type doped layer 20 can be improved, while ensuring the passivation effect of the spacing area 120.

[0103] With reference to Fig. 6 In some embodiments, the spacer area 120 is a groove 121 formed on the back side 12 (that is, the groove 121 is formed on the back side 12 of the silicon wafer 10, and the P-type doped layer 20 and the N-type doped layer 30 are isolated from each other by the groove 121), the passivation film layer 40 covers a side surface 1211 and a bottom surface 1222 of the groove 121, and the thickness of at least some areas of the passivation film layer 40 located on the side surface 1211 of the groove 121 is greater than the thickness of the passivation film layer 40 located on the bottom surface 1212 of the groove 121.

[0104] In this way, the passivation adaptation effect at the slot 121 can be improved, thereby improving the overall passivation performance and improving the performance of the solar cell 100.

[0105] In particular, in such an embodiment, the P-type doped layer 20 typically forms an inner P-type expansion layer (not shown in the figures) in the silicon wafer 10 on the doped layers located on both sides of the groove 121, the N-type doped layer 30 forms an inner N-type expansion layer (not shown in the figures) in the silicon wafer 10, and the inner P-type and inner N-type expansion layers are exposed on the side surface 1211 of the groove 121, so that, in order to improve the passivation effect at the groove 121, the thickness of the passivation film layer 40 on the inner P-type and inner N-type expansion layers exposed from the groove 121 can be increased, thereby improving the electrical performance of the solar cell 100.

[0106] More precisely, the thickness of the passivation film layer 40, located on the inner N-type expansion layer at the groove 121, can be essentially equal to the first thickness D1 or slightly less than the first thickness D1, and the thickness of the passivation film layer 40, located on the inner P-type expansion layer, can be essentially equal to the second thickness D2 or slightly less than the second thickness D2.

[0107] With reference to Fig. 7 In some embodiments, the N-type doped layer 30 can be provided with a first extension section 31 that extends to the top of the groove 121 and floats above the groove 121, and an end section of the first extension section 31 and the surface 311 of the first extension section 31 facing the groove 121 are both provided with a passivation film layer 40, wherein the thickness of the passivation film layer 40 located on the surface 311 of the first extension section 31 facing the groove 121 is greater than the thickness of the passivation film layer 40 located on the bottom surface 1212 of the groove 121. In this way, when the N-type doped layer 30 is provided with the first extension section 31, the passivation effect of the N-type doped layer 30 can be further improved.

[0108] Furthermore, with reference to Fig. 8. In some embodiments, the P-type doped layer 20 is provided with a second extension section 21 that extends to the top of the groove 121 and floats above the groove 121, and an end section of the second extension section 21 and the surface 211 of the second extension section 21 facing the groove 121 are both provided with a passivation film layer 40, wherein the thickness of the passivation film layer 40 located on the surface 211 of the second extension section 21 facing the groove 121 is greater than the thickness of the passivation film layer 40 located on the bottom surface 1212 of the groove 121. In this way, when the P-type doped layer 20 is provided with the second extension section 21, the passivation effect of the P-type doped layer 20 can be further improved.

[0109] With reference to Fig.9 In some embodiments, the spacer area 120 can also be a projection 122 located between the P-type doped layer 20 and the N-type doped layer 30, which are adjacent to each other, a top surface 1221 of the projection 122 being higher than the top surface of the P-type doped layer 20 and the top surface of the N-type doped layer 30, the top surface 1221 and a side surface 1222 of the projection 122 being both provided with a passivation film layer 40, and the thickness of the passivation film layer 40 located on the top surface 1221 of the projection 122 being greater than the thickness of the passivation film layer 40 located on the side surface 1222 of the projection 122.

[0110] In this way, if doping is carried out on the top surface of the projection 122, the passivation effect can be improved by increasing the thickness of the passivation film layer 40 on the top surface. It is understood that the side surface 1222 of the projection 122 refers to a side wall surface of a projecting section of the projection 122 that protrudes from the P-type doped layer 20 and the N-type doped layer 30.

[0111] In the description of this specification, the terms “some embodiments,” “an illustrative embodiment,” “an example,” “a specific example,” or “some examples” mean that certain features, structures, materials, or properties described in connection with the embodiment or example are included in at least one embodiment or example of this disclosure. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Furthermore, the described certain features, structures, materials, or properties may be combined in one or more embodiments or examples in any suitable manner.

[0112] Furthermore, the above descriptions are only preferred embodiments of the present disclosure and are not intended to limit the present disclosure, and any modifications, equivalent replacements, improvements and the like made in the sense and within the framework of the principles of the present disclosure should be included in the scope of protection of the present disclosure. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 202411000880. 2

[0001]

Claims

[1] Solar cell, comprising: a silicon wafer, having a first surface and a second surface opposite each other; P-type doped layers and N-type doped layers arranged on the first surface of the silicon wafer; and a passivation film layer arranged on the P-type doped layers and the N-type doped layers, wherein the passivation film layer has a first thickness on at least some areas of the N-type doped layers, wherein the passivation film layer has a second thickness on at least some areas of the P-type doped layers, and wherein the first thickness is greater than the second thickness. [2] Solar cell according to claim 1, wherein the first surface has a boundary region and an intermediate region, the intermediate region being located on an inside of the boundary region and the boundary region being closer to an edge of the first surface than the intermediate region; and wherein a section of at least one N-type doped layer located on the intermediate region is a first N-type doped section, wherein the passivation film layer located on the first N-type doped section has the first thickness, wherein a section of at least one P-type doped layer located on the intermediate region is a first P-type doped section, and wherein the passivation film layer located on the first P-type doped section has the second thickness. [3] Solar cell according to claim 2, wherein a section of at least one N-type doped layer located on the edge region is a second N-type doped section, wherein the passivation film layer located on the second N-type doped section has a third thickness, wherein a section of at least one P-type doped layer located on the edge region is a second P-type doped section, wherein the passivation film layer located on the second P-type doped section has a fourth thickness, wherein the third thickness is greater than the first thickness and the fourth thickness is greater than the second thickness. [4] Solar cell according to claim 3, wherein the third thickness is greater than the fourth thickness. [5] Solar cell according to claim 2, wherein the passivation film layer covering the intermediate area has an integrated continuous structure. [6] Solar cell according to any one of claims 1 to 5, wherein the ratio of the first thickness to the second thickness is greater than 1 and less than or equal to 2. [7] Solar cell according to claim 6, wherein the ratio of the first thickness to the second thickness is 1.025 to 1.

6. [8] Solar cell according to any one of claims 1 to 5, wherein the difference between the first thickness and the second thickness is 2 nm to 50 nm. [9] Solar cell according to claim 8, wherein the difference between the first thickness and the second thickness is 5 nm to 30 nm. [10] Solar cell according to any one of claims 1 to 5, wherein the first thickness is 52 nm to 250 nm and the second thickness is 50 nm to 200 nm. [11] Solar cell according to claim 10, wherein the first thickness is 55 nm to 230 nm and the second thickness is 50 nm to 200 nm. [12] Solar cell according to claim 2, wherein on the intermediate region there is a space between a P-type doped layer and an N-type doped layer adjacent to each other, wherein the passivation film layer further covers the space, wherein a section of the passivation film layer located on the space has a fifth thickness and wherein the second thickness is greater than the fifth thickness. [13] Solar cell according to claim 12, wherein the passivation film layer on the P-type doped layers, the passivation film layer on the N-type doped layers and the passivation film layer on spacer regions is an integrated continuous structure in the intermediate region. [14] Solar cell according to claim 12, wherein the ratio of the second thickness to the fifth thickness is greater than 1 and less than or equal to 2. [15] Solar cell according to claim 14, wherein the ratio of the second thickness to the fifth thickness is 1.1 to 1.

8. [16] Solar cell according to claim 12, wherein the difference between the second thickness and the fifth thickness is 2 nm to 50 nm. [17] Solar cell according to claim 16, wherein the difference between the second thickness and the fifth thickness is 20 nm to 40 nm. [18] Solar cell according to claim 12, wherein the second thickness is 50 nm to 200 nm and the fifth thickness is 48 nm to 150 nm. [19] Solar cell according to claim 18, wherein the second thickness is 50 nm to 200 nm and the fifth thickness is 30 nm to 160 nm. [20] Solar cell according to claim 12, wherein a specific resistance of the silicon wafer is greater than 20 Ohm·cm and a difference value between the second thickness and the fifth thickness is 10 nm to 60 nm. [21] Solar cell according to claim 12, wherein the spacing region is a groove formed on the first surface, wherein the passivation film layer covers a side surface and a bottom surface of the groove, wherein a thickness of at least some regions of the passivation film layer located on the side surface of the groove is greater than a thickness of the passivation film layer located on the bottom surface of the groove. [22] Solar cell according to claim 21, wherein the solar cell further meets at least one of the following conditions: The N-type doped layer is provided with a first extension section that extends to a top surface of the groove and floats above the groove, and an end section of the first extension section and a surface of the first extension section facing the groove are both provided with the passivation film layer, wherein the thickness of the passivation film layer located on the surface of the first extension section facing the groove is greater than the thickness of the passivation film layer located on the bottom surface of the groove; and the P-type doped layer is provided with a second extension section that extends to the top of the groove and floats above the groove, and an end section of the second extension section and a surface of the second extension section facing the groove are both provided with the passivation film layer, wherein a thickness of the passivation film layer located on the surface of the second extension section facing the groove is greater than the thickness of the passivation film layer located on the bottom surface of the groove. [23] Solar cell according to claim 12, wherein the spacer region is a projection located between the P-type doped layer and the N-type doped layer adjacent to each other, wherein a top surface of the projection is higher than a top surface of the P-type doped layer and a top surface of the N-type doped layer, wherein the top surface and a side surface of the projection are both provided with the passivation film layer and wherein a thickness of the passivation film layer located on the top surface of the projection is greater than a thickness of the passivation film layer located on the side surface of the projection. [24] Solar cell according to claim 2, wherein a section of the passivation film layer located on the intermediate region comprises at least one passivation sublayer of a first type and at least one passivation sublayer of a second type arranged one above the other, and wherein a thickness of the passivation film layer located on the intermediate region is the sum of a thickness of the passivation sublayer of the first type and a thickness of the passivation sublayer of the second type; and a thickness of a section of the passivation sublayer of the first type located on the N-type doped layer is greater than a thickness of a section of the passivation sublayer of the first type located on the P-type doped layer. [25] Solar cell according to claim 24, wherein a thickness of a section of the passivation sublayer of the second type located on the N-type doped layer is equal to a thickness of a section of the passivation sublayer of the second type located on the P-type doped layer. [26] Solar cell according to claim 25, wherein the passivation sublayer of the first type is produced by a Plasma Enhanced Chemical Vapor Deposition (PECVD) process or a thermal growth process and the passivation sublayer of the second type is produced by an atomic deposition process. [27] Solar cell according to one of claims 24 to 26, wherein the passivation sublayer of the first type comprises at least one silicon oxide film layer, a silicon nitride film layer and a silicon oxynitride film layer, and the passivation sublayer of the second type comprises an aluminum oxide film layer. [28] Solar cell according to claim 27, wherein the silicon oxide film layer consists of a plurality of layers of silicon oxide arranged in series, wherein the silicon nitride film layer consists of a plurality of layers of silicon nitride arranged in series, and wherein the silicon oxynitride film layer consists of a plurality of layers of silicon oxynitride arranged in series. [29] Cell arrangement comprising the solar cell according to any one of claims 1 to 28. [30] Photovoltaic system comprising the cell arrangement according to claim 29.

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